18062010
1 <mohi1> [Jun 18 14:24:44] wb juju2143
2 <juju2143> [Jun 18 14:25:12] ...?
3 <mohi1> [Jun 18 14:25:31] juju2143, prepared for today's class??
4 <juju2143> [Jun 18 14:25:37] yeah
5 <mohi1> [Jun 18 14:25:56] cool =]
6 <juju2143> [Jun 18 14:25:59] kinda
7 <juju2143> [Jun 18 14:26:00] :D
8 <mohi1> [Jun 18 14:26:22] ^_^
9 <pedro3005> [Jun 18 15:09:13] hey phillw
10 <phillw> [Jun 18 15:13:24] hi pedro3005
11 <pedro3005> [Jun 18 15:14:20] phillw, how are you?
12 <phillw> [Jun 18 15:16:14] I'm well, been a bit busy with accessibilty coding as I have some one who has experience in it and is willing to help me learn about it.
13 <pedro3005> [Jun 18 15:18:19] Oh, accessibility.. I've never given that a thought
14 <mohi1> [Jun 18 15:20:09] pedro3005, where is Failbot/?
15 <pedro3005> [Jun 18 15:20:42] mohi1, sleeping
16 <mohi1> [Jun 18 15:21:26] argh
17 <pedro3005> [Jun 18 15:21:37] mohi1, why do you want him?
18 <mohi1> [Jun 18 15:22:02] I saw him before 2 months I think. So only asked ya
19 <phillw> [Jun 18 15:44:58] so, do tell, why was there a note for me to log on here in ##devil?
20 <mohi1> [Jun 18 15:45:38] phillw, see the sessions running and guide us please and take some sessions too
21 <mohi1> [Jun 18 15:46:36] juju2143, you have 15 more minutes to start
22 <juju2143> [Jun 18 15:46:57] kay
23 <phillw> [Jun 18 15:47:16] let me know where the logs are and I will have look through them, but I'm no teacher ;-)
24 <phillw> [Jun 18 15:47:22] :-\
25 <mohi1> [Jun 18 15:47:33] phillw, my friend still didn't upload it
26 <mohi1> [Jun 18 15:47:39] am waiting for that
27 <mohi1> [Jun 18 15:47:45] but i can pastebin it now
28 <mohi1> [Jun 18 15:50:08] phillw, read it if you can :P
29 <mohi1> [Jun 18 15:51:56] phillw, my current unknown issue http://ubuntuforums.org/showthread.php?t=1503483&highlight=lucid+compiz+with+GLX
30 <mohi1> [Jun 18 15:52:23] i just get the first two warnings when i run compiz
31 <phillw> [Jun 18 15:53:13] i know nothing about compiz :-\
32 <mohi1> [Jun 18 15:53:22] awwww
33 <mohi1> [Jun 18 15:53:31] pedro3005, how about you?
34 <pedro3005> [Jun 18 15:53:43] even less than phillw
35 <mohi1> [Jun 18 15:53:56] hmmm
36 <phillw> [Jun 18 16:01:08] the 1st time I knew about compiz was in lucid testing when someone told me to do a certain key-combination and I fell off my chair in shock when this 'cube' suddenly appeared... very quickly went back to 2-D :-D
37 <mohi1> [Jun 18 16:02:56] lol phillw
38 <mohi1> [Jun 18 16:03:06] juju2143, ITS TIME!!!!!
39 * bikcmp [Jun 18 16:04:24] teaches Python?
40 <juju2143> [Jun 18 16:04:36] OMG
41 <bikcmp> [Jun 18 16:04:36] even worse, I teach bash :P
42 <bikcmp> [Jun 18 16:04:37] lol
43 <juju2143> [Jun 18 16:04:39] lol
44 <mohi1> [Jun 18 16:04:41] bikcmp, ok at what time?
45 <bikcmp> [Jun 18 16:04:57] mohi1: oh, hehe
46 <bikcmp> [Jun 18 16:05:03] well, i guess i'll do it, when?
47 <bikcmp> [Jun 18 16:05:04] hehe
48 <bikcmp> [Jun 18 16:05:17] if possible, i'd like to do it on my net, freenode's laggy today.
49 <bikcmp> [Jun 18 16:05:18] hehe
50 <juju2143> [Jun 18 16:05:20] Ok, everyone's there?
51 <bikcmp> [Jun 18 16:05:36] er, no, lol, if they'd like, bring them there
52 <mohi1> [Jun 18 16:05:37] pedro3005, ping
53 <bikcmp> [Jun 18 16:05:39] C# sucks btw, lol
54 <bikcmp> [Jun 18 16:05:42] c++ ftw
55 <bikcmp> [Jun 18 16:05:45] and python
56 <juju2143> [Jun 18 16:05:50] bikcmp, of course it's why I teach it
57 <bikcmp> [Jun 18 16:05:57] juju2143: c++?
58 <bikcmp> [Jun 18 16:05:58] hah
59 <mohi1> [Jun 18 16:06:01] lol
60 <juju2143> [Jun 18 16:06:01] C#
61 <bikcmp> [Jun 18 16:06:18] i'm learning C++, since i know python well, I get it :)
62 <mohi1> [Jun 18 16:06:41] juju2143, you can begin
63 <mohi1> [Jun 18 16:06:57] ============================== DAY 2 C# ===========================
64 <juju2143> [Jun 18 16:07:00] Ok, Lesson 2.
65 <bikcmp> [Jun 18 16:07:06] who's actually here? lol
66 <mohi1> [Jun 18 16:07:18] bikcmp, everything is logged
67 <bikcmp> [Jun 18 16:07:24] oh, i see
68 <bikcmp> [Jun 18 16:07:34] see the logs at: ?
69 <juju2143> [Jun 18 16:07:34] Yesterday we looked at our first hello world.
70 <bikcmp> [Jun 18 16:07:36] lol
71 <juju2143> [Jun 18 16:07:41] lol
72 <mohi1> [Jun 18 16:07:49] bikcmp, tomorrow you will get the link :P
73 <bikcmp> [Jun 18 16:07:56] ... goodie
74 <bikcmp> [Jun 18 16:07:57] lol
75 <bikcmp> [Jun 18 16:08:06] i'll teach python side by side with juju2143 :P
76 <bikcmp> [Jun 18 16:08:13] let's see your hello worl d;)
77 <juju2143> [Jun 18 16:08:14] lol:P
78 <mohi1> [Jun 18 16:08:15] juju2143, todays class is about......
79 <juju2143> [Jun 18 16:08:20] Graphics
80 <mohi1> [Jun 18 16:08:24] cool
81 <bikcmp> [Jun 18 16:08:27] in python, print "hello world"
82 <juju2143> [Jun 18 16:08:40] Yesterday, before we left off, we created a new GTK# project
83 <pedro3005> [Jun 18 16:08:42] sorry I'm late
84 <bikcmp> [Jun 18 16:09:00] devilbot: please don't hurt me
85 <devilbot> [Jun 18 16:09:01] bikcmp: Thank you for your request. I have no reason to do that to you.
86 <bikcmp> [Jun 18 16:09:06] rofl
87 <juju2143> [Jun 18 16:09:08] lol.
88 <mohi1> [Jun 18 16:09:13] lol
89 <bikcmp> [Jun 18 16:09:16] devilbot: could you hurt juju2143 though?
90 <devilbot> [Jun 18 16:09:17] bikcmp: Oh. I could but I don't know if I am that interested.
91 <bikcmp> [Jun 18 16:09:22] devilbot: you are intrested.
92 <devilbot> [Jun 18 16:09:24] bikcmp: I will tell my botmaster you said I am intrested.
93 <mohi1> [Jun 18 16:09:25] ;-ai
94 <devilbot> [Jun 18 16:09:26] AI has been turned off
95 <bikcmp> [Jun 18 16:09:29] :(
96 <bikcmp> [Jun 18 16:09:32] bring it on my net? lol
97 <bikcmp> [Jun 18 16:09:40] i could have serious fun with that.
98 <juju2143> [Jun 18 16:09:41] lol
99 <juju2143> [Jun 18 16:09:48] no mine.
100 <mohi1> [Jun 18 16:09:48] bikcmp, ok laterz
101 <bikcmp> [Jun 18 16:09:58] irc.fossnet.info #bots, when you get the time
102 <bikcmp> [Jun 18 16:10:05] now, let's do some C---
103 <pedro3005> [Jun 18 16:10:10] bikcmp, are you experienced with PyGTK? It'd be interesting to have a course in it (seeing we already had a brief python one)
104 <juju2143> [Jun 18 16:10:18] s/irc.fossnet.info/irc.57o9.org/
105 <bikcmp> [Jun 18 16:10:28] pedro3005: I'm pretty bad with graphics in python tbvh.
106 <bikcmp> [Jun 18 16:10:44] i use python mainly for cgi and scripts for administrating my servers. [Jun 18 16:10:44]
107 <bikcmp> [Jun 18 16:10:46] all 5 OF THEM
108 <juju2143> [Jun 18 16:10:50] Ok, day 2: C# language notions.
109 <bikcmp> [Jun 18 16:11:29] ...go on
110 <bikcmp> [Jun 18 16:11:31] lol
111 <juju2143> [Jun 18 16:11:52] damn, my mom jst called me to tell me to go to shower.
112 * bgs100 [Jun 18 19:13:00] notices that it is past 23:00 UTC!
113 <bgs100> [Jun 18 19:13:06] Anyone around?
114 <pedro3005> [Jun 18 19:13:17] hey
115 <bgs100> [Jun 18 19:13:20] seidos, pedro3005 juju2143 mohi2911 ?
116 <bgs100> [Jun 18 19:13:24] Hi pedro3005
117 * bgs100 [Jun 18 19:13:46] looks around
118 <bgs100> [Jun 18 19:14:00] Is anyone else around? :/
119 <pedro3005> [Jun 18 19:19:28] bgs100, this seems wrong to me
120 <pedro3005> [Jun 18 19:20:04] I mean, we're actually offering a free course on C, you'd expect more people to show up
121 <bgs100> [Jun 18 19:20:16] Lol, yeah
122 <bgs100> [Jun 18 19:21:42] hmm
123 <bgs100> [Jun 18 19:22:27] >_>
124 <bgs100> [Jun 18 19:22:30] <_<
125 <pedro3005> [Jun 18 19:22:41] bgs100, I actually have a proposition to make
126 <bgs100> [Jun 18 19:22:48] What?
127 <pedro3005> [Jun 18 19:23:15] bgs100, pm?
128 <bgs100> [Jun 18 19:23:21] Okay
129 <seidos> [Jun 18 19:28:16] I'm here now bgs100, I was eating lunch
130 <seidos> [Jun 18 19:28:28] my mom was kind enough to prepare something
131 <bgs100> [Jun 18 19:29:56] Ohai
132 <bgs100> [Jun 18 19:31:06] pedro3005, seidos So want to do the C class today?
133 <seidos> [Jun 18 19:32:57] I'm game if pedro's game
134 <pedro3005> [Jun 18 19:33:22] I'm in
135 <bgs100> [Jun 18 19:33:35] Alright, cool
136 <seidos> [Jun 18 19:33:39] hey bgs100 are you employed?
137 <bgs100> [Jun 18 19:34:01] No, not old enough to be.
138 <seidos> [Jun 18 19:34:10] ah
139 <bgs100> [Jun 18 19:34:22] Okay
140 <seidos> [Jun 18 19:34:34] how old are you? I thought you were 100 :P
141 <bgs100> [Jun 18 19:34:39] Lol
142 <bgs100> [Jun 18 19:34:47] Naw, I'm just
143 <bgs100> [Jun 18 19:34:52] 9000!!!!!!
144 <bgs100> [Jun 18 19:34:54] (jk)
145 <bgs100> [Jun 18 19:34:59] Anyway
146 <bgs100> [Jun 18 19:35:05] seidos, Do you have the homework?
147 <seidos> [Jun 18 19:35:16] yeah, but I couldn't get it to work right
148 <bgs100> [Jun 18 19:35:24] hm
149 <bgs100> [Jun 18 19:35:28] Pastebin?
150 <seidos> [Jun 18 19:35:33] an if statement isn't executing and I don't know why
151 <seidos> [Jun 18 19:35:45] all right let me pastebin
152 <bgs100> [Jun 18 19:36:28] Okay
153 <seidos> [Jun 18 19:38:23] http://paste.ubuntu.com/451829/
154 <seidos> [Jun 18 19:38:50] bgs100 ^^
155 <bgs100> [Jun 18 19:39:02] Okay
156 <bgs100> [Jun 18 19:40:42] seidos, It's because,
157 <bgs100> [Jun 18 19:42:23] you're scanf()'ing within the if statement for them getting it wrong, so the other if isn't executed, then the next time it loops, it sees that num1 is the same as secret, so stops, and then the program ends
158 <bgs100> [Jun 18 19:42:33] Also, if they get it right the first time,
159 <bgs100> [Jun 18 19:42:53] then num1 == secret at the beginning of the first loop, so the body never runs
160 <bgs100> [Jun 18 19:43:55] You could fix this by, instead of having and else if saying they won, butting the printf() after the for loop, which means they were successful.
161 <bgs100> [Jun 18 19:45:00] And then, you don't need the first if statement because it's asking the same thing as the loop.
162 <bgs100> [Jun 18 19:45:20] (you need to keep the body of it, though)
163 <bgs100> [Jun 18 19:47:16] seidos ?
164 <seidos> [Jun 18 19:47:23] yeah, I'm reading what you wrote
165 <seidos> [Jun 18 19:47:27] I'm also on the phone
166 <bgs100> [Jun 18 19:47:40] Ah
167 <seidos> [Jun 18 19:47:55] my friend is a teacher and had a tough day
168 <seidos> [Jun 18 19:48:04] 8th graders
169 <seidos> [Jun 18 19:48:12] at an inner city school
170 <bgs100> [Jun 18 19:48:20] Ah...
171 <bgs100> [Jun 18 19:48:43] Well, here's the fixed version (also removing the unused variable i):
172 <bgs100> [Jun 18 19:48:47] http://paste.ubuntu.com/451833/
173 <bgs100> [Jun 18 19:49:02] Oh crap...
174 <bgs100> [Jun 18 19:49:08] g2g, pedro3005 seidos ...
175 <bgs100> [Jun 18 19:49:10] Sorry :(
176 <bgs100> [Jun 18 19:49:19] Hopefully will be back
177 <bgs100> [Jun 18 19:49:22] soon
178 <pedro3005> [Jun 18 19:49:23] ah no problem bgs100
179 <pedro3005> [Jun 18 19:49:34] thanks
180 <seidos> [Jun 18 19:49:35] thank you
181 <pedro3005> [Jun 18 19:49:41] I'll brb then
182 <pedro3005> [Jun 18 19:49:42] :D
183 <bgs100> [Jun 18 19:49:57] np, but still sorry... hopefully be back in ajust a few minutes...
184 <bgs100> [Jun 18 20:07:50] Back
185 <bgs100> [Jun 18 20:07:55] pedro3005, seidos Ping
186 <bgs100> [Jun 18 20:09:08] ...
187 <seidos> [Jun 18 20:13:53] sorry dude, still on the phone :|
188 <bgs100> [Jun 18 20:19:06] Oh
189 <seidos> [Jun 18 20:28:44] okay I'm off
190 <seidos> [Jun 18 20:28:54] sorry
191 <seidos> [Jun 18 20:29:11] ha, you're probably not here anymore :D
192 <bgs100> [Jun 18 20:30:04] Yes
193 <bgs100> [Jun 18 20:30:05] I am
194 <bgs100> [Jun 18 20:30:12] seidos, ^
195 <bgs100> [Jun 18 20:30:39] pedro3005, Are you here?
196 * bgs100 [Jun 18 20:30:53] looks at attendance roll and seating chart
197 <pedro3005> [Jun 18 20:37:02] bgs100, hi
198 <bgs100> [Jun 18 20:37:29] Hai
199 * bgs100 [Jun 18 20:37:38] wonders where seidos ran off to
200 <seidos> [Jun 18 20:37:55] hey
201 <bgs100> [Jun 18 20:37:57] pedro3005, Alright, well, ready to continue?
202 <bgs100> [Jun 18 20:38:01] Yay!
203 <pedro3005> [Jun 18 20:38:01] sure
204 <seidos> [Jun 18 20:38:03] just watching this video on DNA
205 <bgs100> [Jun 18 20:38:05] seidos, Ready?
206 <bgs100> [Jun 18 20:38:08] Ah
207 <seidos> [Jun 18 20:38:29] oh man, I need to download your code that fixed my HW
208 <bgs100> [Jun 18 20:39:22] http://paste.ubuntu.com/451833/
209 <seidos> [Jun 18 20:39:47] I'm pretty disappointed, I thought the fix would be easier
210 <seidos> [Jun 18 20:39:51] I really thought I was close
211 <bgs100> [Jun 18 20:39:57] seidos, You were
212 <bgs100> [Jun 18 20:40:07] In all,
213 <bgs100> [Jun 18 20:40:17] you could have fixed it just by moving one line of code
214 <seidos> [Jun 18 20:40:30] by moving a line of code, huh?
215 <seidos> [Jun 18 20:40:54] why did you change it to a while loop?
216 <bgs100> [Jun 18 20:41:09] Because i wasn't necessary
217 <bgs100> [Jun 18 20:41:19] (the variable i)
218 <bgs100> [Jun 18 20:41:25] You didn't do anything with it.
219 <pedro3005> [Jun 18 20:41:35] #define print printf
220 <pedro3005> [Jun 18 20:41:36] ?!
221 <seidos> [Jun 18 20:41:48] ahhhh
222 <bgs100> [Jun 18 20:41:52] pedro3005, Oh,
223 <bgs100> [Jun 18 20:42:02] seidos was getting print mixed up with printf,
224 <seidos> [Jun 18 20:42:03] bgs100 taught me that
225 <seidos> [Jun 18 20:42:21] I put it in just to be..."creative"
226 <seidos> [Jun 18 20:42:31] :P
227 <bgs100> [Jun 18 20:42:32] so I told seidos they could do that (as a neat thing, I recommended seidos learns to type printf :p)
228 <pedro3005> [Jun 18 20:42:37] bgs100, doesn't look like the greatest idea lol
229 <bgs100> [Jun 18 20:42:39] s/they/he/
230 <bgs100> [Jun 18 20:42:55] pedro3005, It was something neat I decided to show seidos :p
231 <pedro3005> [Jun 18 20:43:14] ok
232 <bgs100> [Jun 18 20:43:14] ANYWAY
233 <pedro3005> [Jun 18 20:43:25] seidos, you probably shouldn't use it regularly though
234 <seidos> [Jun 18 20:43:58] pedro3005, I don't think it will really matter.
235 <bgs100> [Jun 18 20:45:35] Okay
236 <bgs100> [Jun 18 20:45:36] So
237 <bgs100> [Jun 18 20:45:45] -----------------------------------------THE STANDARD LIBRARY!------------------------------------------
238 <bgs100> [Jun 18 20:45:49] *angels sing*
239 <bgs100> [Jun 18 20:47:02] So
240 <bgs100> [Jun 18 20:47:04] Yeah
241 <bgs100> [Jun 18 20:47:31] Open up a shiny new text file
242 <bgs100> [Jun 18 20:47:38] And I will pastebin the code
243 <pedro3005> [Jun 18 20:49:02] bgs100, I just saw someone do char** argv, does that work?
244 <bgs100> [Jun 18 20:49:11] Yeap
245 <bgs100> [Jun 18 20:49:23] Remember, array secretly == pointer
246 <bgs100> [Jun 18 20:49:38] so argv[][], *argv[], and **argv are all the same
247 <pedro3005> [Jun 18 20:50:19] ok
248 <seidos> [Jun 18 20:51:03] ...hmmm doesn't really make sense, but I'll trust you
249 <bgs100> [Jun 18 20:51:23] It will later, so trust me then too
250 <seidos> [Jun 18 20:52:51] ok
251 <bgs100> [Jun 18 20:55:09] Okay, here ya go:
252 <bgs100> [Jun 18 20:55:38] http://pastebin.com/RP0X57Dd
253 <bgs100> [Jun 18 20:55:39] SCRO
254 <bgs100> [Jun 18 20:55:45] pedro3005, seidos ^^^
255 <pedro3005> [Jun 18 20:57:20] bgs100, why did you import time.h? it's not necessary
256 <bgs100> [Jun 18 20:57:32] Yes, it is.
257 <pedro3005> [Jun 18 20:57:55] well, it compiles and runs without
258 <pedro3005> [Jun 18 20:58:02] although it bitches
259 <bgs100> [Jun 18 20:58:05] Yes
260 <bgs100> [Jun 18 20:58:12] it b*tches for a reason.
261 <pedro3005> [Jun 18 20:58:48] bgs100, well, I understand the code :D
262 <bgs100> [Jun 18 20:59:22] pedro3005, Do you understand srand(time(NULL)); ?
263 <pedro3005> [Jun 18 20:59:28] yeah
264 <bgs100> [Jun 18 20:59:32] Okay
265 <seidos> [Jun 18 20:59:34] I kind of understand it
266 <bgs100> [Jun 18 20:59:41] time.h is what provides time(NULL)
267 <bgs100> [Jun 18 20:59:44] er, time()
268 <seidos> [Jun 18 20:59:54] what does srand(time(NULL)) do?
269 <seidos> [Jun 18 20:59:58] anything?
270 <bgs100> [Jun 18 21:00:04] Yes, one sec
271 <pedro3005> [Jun 18 21:00:05] it's essential
272 <pedro3005> [Jun 18 21:00:10] it defines the seed of rand
273 <pedro3005> [Jun 18 21:00:18] that is, where rand will get its numbers from
274 <bgs100> [Jun 18 21:00:22] Who's the teacher here? :P
275 <bgs100> [Jun 18 21:00:28] pedro3005, Eh,
276 <bgs100> [Jun 18 21:00:34] not 'where'
277 <pedro3005> [Jun 18 21:00:42] in this case, the seemingly random number is generated from the time the code is being run, I guess
278 <bgs100> [Jun 18 21:00:53] Yes
279 <bgs100> [Jun 18 21:00:57] ANYWAY
280 <pedro3005> [Jun 18 21:01:05] bgs100, why not 'where'?
281 <bgs100> [Jun 18 21:01:23] pedro3005, Since time.h standard gcc is a nice compiler and will let you get by with not including it, but it's bad practice not to when you're using it's definitions.
282 <pedro3005> [Jun 18 21:01:37] ok
283 <bgs100> [Jun 18 21:01:41] pedro3005, It just provides a starting number for rand and such to do lots of odd math on
284 <bgs100> [Jun 18 21:01:50] A 'seed'
285 <pedro3005> [Jun 18 21:01:59] okay
286 <bgs100> [Jun 18 21:04:12] Okay
287 <bgs100> [Jun 18 21:04:13] So
288 <bgs100> [Jun 18 21:04:39] In this source, you'll notice we have included so different files
289 <bgs100> [Jun 18 21:05:10] stdlib.h, and time.h
290 <bgs100> [Jun 18 21:05:21] stdlib.h for the functions rand and srand,
291 <bgs100> [Jun 18 21:05:31] time.h for time()
292 <bgs100> [Jun 18 21:05:48] I just explained what srand does,
293 <bgs100> [Jun 18 21:06:42] rand() returns a not-actually-random number
294 <bgs100> [Jun 18 21:06:57] based (originally) on what srand was given
295 <seidos> [Jun 18 21:07:23] right, a quasi random number
296 <bgs100> [Jun 18 21:07:47] *nodes* time() is a function that, when passed NULL (Null is actually 0, but it represents some fancy stuff that has to do with pointers), return the number of seconds since this one arbitary date,
297 <seidos> [Jun 18 21:08:15] *nodes*?
298 <bgs100> [Jun 18 21:08:17] 00:00:00 UTC, January 1, 1970
299 <bgs100> [Jun 18 21:08:22] seidos,
300 <bgs100> [Jun 18 21:08:25] I meant *nods*
301 <bgs100> [Jun 18 21:08:27] sorry :p
302 * seidos [Jun 18 21:08:46] nods
303 * bgs100 [Jun 18 21:08:56] nods back
304 <bgs100> [Jun 18 21:09:01] Anyway
305 <bgs100> [Jun 18 21:09:24] So, the number of seconds since 1970 is a number that the user probably isn't exactly counting out.
306 <bgs100> [Jun 18 21:09:33] Ohai Snova
307 <bgs100> [Jun 18 21:09:58] Anyway
308 <seidos> [Jun 18 21:10:20] ooookay
309 <bgs100> [Jun 18 21:10:44] It's very often used as the random seed.
310 <seidos> [Jun 18 21:10:54] so it will be quasi random because the user won't be trying to figure out the number of seconds on the clock
311 <seidos> [Jun 18 21:11:11] or the difference in seconds
312 <pedro3005> [Jun 18 21:11:17] why do you get the rest of its division by 100?
313 <pedro3005> [Jun 18 21:11:26] also, can't you set a range to rand()?
314 <bgs100> [Jun 18 21:11:30] No.
315 <bgs100> [Jun 18 21:11:42] C does not have optional arguments.
316 <pedro3005> [Jun 18 21:11:50] that bastard
317 * bgs100 [Jun 18 21:12:07] takes away pedro3005's star "no cursing in class"
318 <bgs100> [Jun 18 21:12:16] seidos, Yeah, that number itself will seem quite random, and then rand() does magic weird math to it, also
319 <pedro3005> [Jun 18 21:12:16] bgs100, cursing
320 <pedro3005> [Jun 18 21:12:19] C is okay
321 <bgs100> [Jun 18 21:12:31] anyway
322 <seidos> [Jun 18 21:12:37] especially since it doesn't do anything
323 <pedro3005> [Jun 18 21:12:58] bgs100, so it'll come up with virtually anything?
324 * seidos [Jun 18 21:13:01] laughs at pedro3005 as his words fall away before hitting C
325 <bgs100> [Jun 18 21:13:02] pedro3005, We mod it by 100 so it will be in the range of 0 to 99, inclusive
326 <bgs100> [Jun 18 21:13:05] pedro3005, yeah
327 <seidos> [Jun 18 21:13:27] modulus?
328 <bgs100> [Jun 18 21:13:38] seidos, Yep
329 <pedro3005> [Jun 18 21:13:45] bgs100, it'll be definitely in the range?
330 <bgs100> [Jun 18 21:13:52] And then we add 1 to make it within the range of 1 - 100.
331 <seidos> [Jun 18 21:14:01] I have hard time doing mods in my head
332 <bgs100> [Jun 18 21:14:01] pedro3005, If not, something very serious is wrong.
333 <seidos> [Jun 18 21:14:15] but then, I have a hard time even doing some pretty basic arithmetic
334 <pedro3005> [Jun 18 21:14:18] bgs100, that % is the same % as 10 % 3 = 1?
335 * bgs100 [Jun 18 21:14:22] gives seidos a free calculator
336 <bgs100> [Jun 18 21:14:34] pedro3005, Yes
337 <pedro3005> [Jun 18 21:14:41] I don't get why it works
338 <seidos> [Jun 18 21:14:43] I tried dividing 750,000,000,000 by 150,000,000 today and had to check on my calculator to make sure it was 5000
339 * bgs100 [Jun 18 21:15:08] shrugs
340 <bgs100> [Jun 18 21:15:19] I would've double-checked too
341 <bgs100> [Jun 18 21:15:25] Anyway
342 <bgs100> [Jun 18 21:15:30] pedro3005, What do you mean?
343 <pedro3005> [Jun 18 21:15:33] I see that it works
344 <pedro3005> [Jun 18 21:15:43] but why is it never > 99?
345 <bgs100> [Jun 18 21:16:01] Well hopefully it should be able to be 100, thanks to that +1
346 <seidos> [Jun 18 21:16:12] it must be the % function
347 <seidos> [Jun 18 21:16:15] er operator
348 <pedro3005> [Jun 18 21:16:16] well, you get what I mean
349 <pedro3005> [Jun 18 21:16:18] >.>
350 <bgs100> [Jun 18 21:16:27] Yeah
351 <bgs100> [Jun 18 21:16:28] Okay
352 * bgs100 [Jun 18 21:16:35] switches to, uh, math class mode
353 <bgs100> [Jun 18 21:17:27] brb
354 <Snova> [Jun 18 21:18:59] % is division that results in the remainder, rather than the quotient [Jun 18 21:18:59]
355 <bgs100> [Jun 18 21:19:10] back
356 <Snova> [Jun 18 21:19:23] if you moduli by 100 then you can't get a number above 100; such a number would have increased the quotient, no?
357 * bgs100 [Jun 18 21:19:40] notices teaching assistance
358 <seidos> [Jun 18 21:20:06] which one is the quotient? denominator?
359 <bgs100> [Jun 18 21:20:17] er
360 <Snova> [Jun 18 21:20:42] consider 150/100; quotient would be 1.5 or 1; remainder is 50
361 <seidos> [Jun 18 21:20:48] hey fractions might help, if it's a whole fraction, there is no remainder
362 <seidos> [Jun 18 21:21:04] ah dang it, quotient is the result
363 <Snova> [Jun 18 21:21:21] i may have my terminology slightly incorrect; the point is % takes the remainder and is a convenient way to keep numbers within a certain range
364 <seidos> [Jun 18 21:21:52] I need to do some more examples to solidify my understanding of %
365 <pedro3005> [Jun 18 21:21:55] Oh I see
366 <bgs100> [Jun 18 21:22:04] pedro3005, If you multiply 100 as many times as it will go into n, and then take the difference, it can't be larger than greater than/equal to 100 or 100 would have gone in more times.
367 <pedro3005> [Jun 18 21:22:14] yeah
368 <pedro3005> [Jun 18 21:22:19] I understand now
369 <seidos> [Jun 18 21:22:23] can you give me some more % examples?
370 <Snova> [Jun 18 21:22:23] seidos: 150 / 100 = 1r50; 150 % 100 = 50
371 <bgs100> [Jun 18 21:22:24] Good
372 <bgs100> [Jun 18 21:22:55] Somewhat ironically, I was about to bring up math.h
373 <seidos> [Jun 18 21:23:12] like 2 % 1 -> 2/1 = 2 so 2 % 1 = 0
374 <Snova> [Jun 18 21:23:30] yep
375 <seidos> [Jun 18 21:23:54] that's an easy one to understand and remember since there is no remainder
376 * bgs100 [Jun 18 21:23:55] prepares to disengage math class mode
377 <seidos> [Jun 18 21:24:08] I don't tend to think in terms of remainders anymore
378 * seidos [Jun 18 21:24:19] gets out of the way so he doesn't get hurt
379 <Snova> [Jun 18 21:24:20] modulo arithmetic actually comes up quite a lot; for example- a byte has 8 bits and a range of 0-255 (inclusive); what do you get if you increment a byte containing 255?
380 <pedro3005> [Jun 18 21:24:56] two bytes?
381 <seidos> [Jun 18 21:25:05] 16 bits?
382 <seidos> [Jun 18 21:25:17] :P same diff as pedro3005's answer
383 <Snova> [Jun 18 21:25:25] you wish; it's zero
384 <seidos> [Jun 18 21:25:42] whoa
385 <Snova> [Jun 18 21:25:46] it's also been described as clock math; where 11 + 3 = 2
386 <Snova> [Jun 18 21:25:55] because it's actually (11 + 3) % 12 = 2
387 <seidos> [Jun 18 21:25:55] isn't there some overflow buffer or something?
388 <Snova> [Jun 18 21:26:05] no, that's why you have larger numbers
389 <Snova> [Jun 18 21:26:08] er, larger types
390 <seidos> [Jun 18 21:26:27] so the same is true for an int?
391 <Snova> [Jun 18 21:26:35] a byte is a byte is a byte; the most the cpu will do for you is set a flag informing you that the operation overflowed
392 <bgs100> [Jun 18 21:26:37] seidos, Yes
393 <bgs100> [Jun 18 21:26:47] Get a big enough int and suddenly you have a negative number
394 <seidos> [Jun 18 21:26:48] if you try to increment an int (what's the limit 65,xxx?), it will evaluate to 0?
395 <Snova> [Jun 18 21:26:57] shorts have 16 bits and a limit of ~65000
396 <Snova> [Jun 18 21:27:08] er, unsigned ones
397 <Snova> [Jun 18 21:27:18] unsigned ints (32 bits) are about 4 billion; signed ones half that
398 <Snova> [Jun 18 21:27:41] anyway, are we done with math class yet? :)
399 <seidos> [Jun 18 21:27:43] whoa, I didn't know that. never thought of what would happen if you overflowed it.
400 <pedro3005> [Jun 18 21:27:43] well, I don't know what is unsigned/signed
401 <bgs100> [Jun 18 21:27:54] pedro3005,,
402 <Snova> [Jun 18 21:28:03] pedro3005: sign is a binary state (positive, negative), so signed ints use one bit to represent that
403 <seidos> [Jun 18 21:28:08] me neither, I assume signed has something to do with data integrity
404 <bgs100> [Jun 18 21:28:17] Signed = One bit is dedicated to representing whether the number is positive or negative or not,
405 <seidos> [Jun 18 21:28:24] how do you declare a signed int?
406 <pedro3005> [Jun 18 21:28:34] 'int' I guess
407 <bgs100> [Jun 18 21:28:35] seidos, They are signed by default.
408 <Snova> [Jun 18 21:28:35] "int" or "signed int"; they're signed by default until you say "unsigned int"
409 <seidos> [Jun 18 21:28:39] is it like sint number:
410 <pedro3005> [Jun 18 21:28:48] bgs100, so an unsigned int is always positive?
411 <bgs100> [Jun 18 21:28:54] pedro3005, Or 0.
412 <Snova> [Jun 18 21:28:58] pedro3005: and guess what happens if you overflow it?
413 <pedro3005> [Jun 18 21:29:15] it becomes 0?
414 <Snova> [Jun 18 21:29:19] or larger, but yes
415 * bgs100 [Jun 18 21:29:25] gives pedro3005 star back
416 <seidos> [Jun 18 21:29:42] the same thing happens to signed and unsigned variables?
417 <Snova> [Jun 18 21:29:46] conveniently enough (or not), the sign bit is at the "top end" of ints, so if you overflow them you actually turn them negative
418 <seidos> [Jun 18 21:29:52] if overflowed they evaluate to 0?
419 <pedro3005> [Jun 18 21:30:30] But is overflowing an actual danger we should be on the lookout for?
420 <seidos> [Jun 18 21:30:39] you mean the sign bit negative, but not the actual value of the int right?
421 <Snova> [Jun 18 21:30:41] 2147483647 is the maximum positive number a signed int can hold; if you increment that by one you get -2147483647 or something
422 <Snova> [Jun 18 21:30:47] pedro3005: only if you're dealing with really big numbers, usually
423 <bgs100> [Jun 18 21:30:57] pedro3005, Probably not.
424 <seidos> [Jun 18 21:30:59] pedro3005, it had something to do % math
425 <Snova> [Jun 18 21:32:11] pedro3005: if you're using normal ints you'd have to be dealing with numbers beyond 4 billion and something; if it becomes a problem unsigned 64-bit ints have a range of 18,446,744,073,709,551,615 (eighteen quintillion?) and if you go beyond *that*- there are "bigint" libraries to handle it
426 <bgs100> [Jun 18 21:32:29] Wheeeeeeeee
427 <seidos> [Jun 18 21:32:41] I couldn't even imagine applications that would use 18,446,744,073,709,551,615
428 <Snova> [Jun 18 21:32:57] the lesson: don't use small ints (shorts, chars) unless you actually have a reason to, and if you get weird negative numbers you might be overflowing something
429 <pedro3005> [Jun 18 21:33:02] there is one part of physics which weighs the universe
430 <pedro3005> [Jun 18 21:33:04] :P
431 <pedro3005> [Jun 18 21:33:34] bgs100, go on
432 <seidos> [Jun 18 21:34:14] makes me wonder how many bits it would need to handle a googol
433 <seidos> [Jun 18 21:34:19] I think that's how it's spelled
434 <bgs100> [Jun 18 21:34:39] Okay
435 <bgs100> [Jun 18 21:34:41] Well
436 <bgs100> [Jun 18 21:35:50] Onto math.h
437 <bgs100> [Jun 18 21:35:56] One sec
438 <Snova> [Jun 18 21:36:03] seidos: 333
439 <seidos> [Jun 18 21:36:43] Snova, how did you figure it out?
440 <Snova> [Jun 18 21:37:28] seidos: math.log(10**100, 2) in python
441 <bgs100> [Jun 18 21:37:34] Snova, !
442 <pedro3005> [Jun 18 21:37:44] On a side note, what are your favorite IDEs/text editors/however you like to program
443 <bgs100> [Jun 18 21:37:53] You're going to make my students want to go to a python class instead!
444 <pedro3005> [Jun 18 21:38:10] I bet it's like 30 lines of code in
445 <pedro3005> [Jun 18 21:38:11] C
446 <Snova> [Jun 18 21:38:12] bgs100: what? I don't know the mathematical notation for logarithms of arbitrary bases :) (or C for that matter)
447 <pedro3005> [Jun 18 21:38:18] god damn it I fail at typing today
448 <bgs100> [Jun 18 21:38:27] pedro3005, Actually, no.
449 <bgs100> [Jun 18 21:38:32] In fact
450 <Snova> [Jun 18 21:38:35] pedro3005: C has log(), I just don't know how to get a logarithm for something other than base 10 in C
451 <bgs100> [Jun 18 21:38:39] Great introduction to math.h
452 <pedro3005> [Jun 18 21:38:55] I'm trying out Netbeans and it just screams "bloated"
453 <bgs100> [Jun 18 21:39:07] Lol
454 <Snova> [Jun 18 21:39:27] pedro3005: just because C is "lower-level" doesn't mean it requires reams of code; I've heard of assembly languages that were more compact than C
455 <seidos> [Jun 18 21:40:01] I just tried math.log(10**100, 2) in python and it didn't work
456 <Snova> [Jun 18 21:40:21] import math; math.log(10**100, 2)
457 <bgs100> [Jun 18 21:40:22] seidos, import math
458 <seidos> [Jun 18 21:40:34] crud, I was trying use math for some reason
459 <seidos> [Jun 18 21:40:38] thanks
460 <seidos> [Jun 18 21:41:12] man I suck at logs
461 <pedro3005> [Jun 18 21:41:12] I don't really know what a log is
462 <bgs100> [Jun 18 21:41:25] logarithm; the inverse of exponentiation
463 <Snova> [Jun 18 21:41:26] pedro3005: think of it as the inverse of exponentiation
464 <Snova> [Jun 18 21:41:29] bah!
465 <seidos> [Jun 18 21:41:35] it's like the log has a base, the base in the number
466 <bgs100> [Jun 18 21:41:40] Snova, :D
467 <Snova> [Jun 18 21:41:44] pedro3005: if x^y = z then log(z, y) = x
468 <pedro3005> [Jun 18 21:41:46] Snova, bgs100 won this round :p
469 <seidos> [Jun 18 21:41:48] what's the general form?
470 <seidos> [Jun 18 21:41:55] yeah, that's it
471 <bgs100> [Jun 18 21:42:03] pedro3005, 5 to the power of 6 = 15625, and 15625 log 5 = 6
472 <bgs100> [Jun 18 21:42:11] log (base) 5
473 <seidos> [Jun 18 21:42:12] I always forget it after I look at it and figure it out
474 <seidos> [Jun 18 21:42:21] it's like my brain wasn't designed for logs
475 <pedro3005> [Jun 18 21:42:23] Alright
476 <Snova> [Jun 18 21:42:39] bgs100: is that the notation? seidos's query would be "10^100 log 2" then
477 <seidos> [Jun 18 21:43:09] I don't get what math.log is doing
478 <seidos> [Jun 18 21:43:20] is it taking log 2 of 10^100?
479 <seidos> [Jun 18 21:43:21] must be
480 <Snova> [Jun 18 21:43:23] yes
481 <Snova> [Jun 18 21:43:49] you wanted to know how many bits that would take. to find out the numerical range of a given number of bits, take 2^bits
482 <Snova> [Jun 18 21:44:03] so you want to know; 2^bits = 10^100
483 <Snova> [Jun 18 21:44:17] which is a simple application of a logarithm; 10^100 log 2
484 <seidos> [Jun 18 21:44:17] yeah that's what I was doing, I was stupidly putting 2^x and substituting values of x
485 <Snova> [Jun 18 21:44:36] I've done it; now you know a better way
486 <seidos> [Jun 18 21:44:47] I didn't even think logarithms were applicable
487 <seidos> [Jun 18 21:44:59] unfortunately, I don't, I have to spend some time rethinking about logs to relearn them
488 <Snova> [Jun 18 21:45:03] we might not be moving through C very quickly, but at least we're getting some math in :p (some of it is foundational though, especially modulo arithmetic)
489 <seidos> [Jun 18 21:45:51] hey Snova do you have a job?
490 <Snova> [Jun 18 21:45:55] nope
491 <seidos> [Jun 18 21:46:05] how old are you?
492 <Snova> [Jun 18 21:46:29] 10 < x < 20
493 <Snova> [Jun 18 21:46:40] and older every second
494 <pedro3005> [Jun 18 21:46:42] seidos, why do you keep asking that to everyone?
495 <Snova> [Jun 18 21:47:17] pedro3005: it's nice to have some idea of who you're talking to
496 <seidos> [Jun 18 21:47:24] because I'm 31 and live with my mom :D
497 <seidos> [Jun 18 21:47:41] it makes me wonder how smart the 31 year old programmers are
498 <seidos> [Jun 18 21:48:21] if I knew c I'm sure I could find a job somewhere
499 <pedro3005> [Jun 18 21:48:24] Snova, seems to me like lots of people aren't really comfortable saying their ages / etc
500 <Snova> [Jun 18 21:48:53] pedro3005: true
501 <seidos> [Jun 18 21:48:57] I think if I had more scruples I'd be embarrassed of my age
502 <seidos> [Jun 18 21:49:06] but I think I'm too old to care
503 <pedro3005> [Jun 18 21:49:28] aaaaaand back to C :P I'm almost falling asleep on my chair
504 <bgs100> [Jun 18 21:49:33] #include <stdio.h>
505 <bgs100> [Jun 18 21:49:33] #include <math.h>
506 <bgs100> [Jun 18 21:49:33] int main() {
507 <bgs100> [Jun 18 21:49:33] printf("Square root of 25: %d\n", (int)sqrt(25));
508 <bgs100> [Jun 18 21:49:33] printf("Sine of 42: %g\n", sin(42));
509 <bgs100> [Jun 18 21:49:34] printf("93.2 rounded up: %d\n", (int)ceil(93.2));
510 <bgs100> [Jun 18 21:49:36] printf("2 to the power of 333: %ld\n", (long)pow(2, 333));
511 <bgs100> [Jun 18 21:49:38] return 0;
512 <bgs100> [Jun 18 21:49:40] }
513 <bgs100> [Jun 18 21:49:42] ERRR
514 <bgs100> [Jun 18 21:49:44] CRAP
515 <bgs100> [Jun 18 21:49:48] That was supposed to be a pastebin link :|
516 <bgs100> [Jun 18 21:49:58] So ignore all of that
517 <bgs100> [Jun 18 21:50:14] http://pastebin.com/UF0eCknA
518 <bgs100> [Jun 18 21:50:41] pedro3005, seidos SCRO , but add this to your compile command: " -lm"
519 <pedro3005> [Jun 18 21:51:24] Sine of 42: -0.916522
520 <pedro3005> [Jun 18 21:51:36] isn't it supposed to be positive?
521 <bgs100> [Jun 18 21:51:55] I don't know much about sines and such :p
522 <Snova> [Jun 18 21:52:00] not according to python
523 <Snova> [Jun 18 21:52:08] also, yes
524 <pedro3005> [Jun 18 21:52:19] Well, if you draw the circle, the first quadrant has positive sine and cosines
525 <pedro3005> [Jun 18 21:52:25] since x and y are positives
526 <pedro3005> [Jun 18 21:52:30] 42 is in the first quadrant
527 <Snova> [Jun 18 21:52:34] hm, that would make sense
528 <bgs100> [Jun 18 21:52:56] Um
529 <bgs100> [Jun 18 21:53:01] Notice the last line
530 <bgs100> [Jun 18 21:53:17] (that's the error I *wanted* you to find)
531 <bgs100> [Jun 18 21:53:26] 2 to the power of 333: 2147483647
532 <Snova> [Jun 18 21:53:31] hehe
533 <seidos> [Jun 18 21:53:33] 42 is in the first quadrant but -.916 is in the 4th
534 <bgs100> [Jun 18 21:53:39] There's the magic number referenced earlier ;)
535 <bgs100> [Jun 18 21:54:29] Anyway
536 <bgs100> [Jun 18 21:54:39] Maybe I shouldn't have gone into math.h...
537 <bgs100> [Jun 18 21:54:46] :P
538 <pedro3005> [Jun 18 21:54:46] bgs100, oh yeah, googol
539 <pedro3005> [Jun 18 21:54:52] why is it wrong?
540 <bgs100> [Jun 18 21:54:59] Ahem,
541 <pedro3005> [Jun 18 21:55:10] google also says sine of 42 is negative
542 <Snova> [Jun 18 21:55:13] pedro3005: note that number is 2**31 - 1; i.e. it's the maximum of a signed int
543 <bgs100> [Jun 18 21:55:15] <Snova> 2147483647 is the maximum positive number a signed int can hold
544 <pedro3005> [Jun 18 21:55:31] oh, right
545 <seidos> [Jun 18 21:56:25] why is it 2^333?
546 <seidos> [Jun 18 21:56:39] shouldn't it be something to do with 32bit?
547 <pedro3005> [Jun 18 21:56:47] bgs100 chose 2^333
548 <Snova> [Jun 18 21:56:48] in theory you'd get 10^100 with that, a googol
549 <seidos> [Jun 18 21:56:56] ah
550 <Snova> [Jun 18 21:56:57] it is meant to illustrate integer limits
551 <bgs100> [Jun 18 21:57:03] Yeah
552 <seidos> [Jun 18 21:57:06] so it didn't overflow
553 <seidos> [Jun 18 21:57:13] I mean, it stopped at the maximum
554 <bgs100> [Jun 18 21:57:20] Apparently not
555 <pedro3005> [Jun 18 21:57:49] if I try to change it to unsigned long, it says 2^333 = -1
556 <Snova> [Jun 18 21:57:56] that is the result of an implementation detail in pow()
557 <Snova> [Jun 18 21:57:58] "If the result overflows, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with the mathematically correct sign."
558 <seidos> [Jun 18 21:58:56] what's pow()
559 <bgs100> [Jun 18 21:58:57] Hm,
560 <Snova> [Jun 18 21:59:00] exponentiation
561 <Snova> [Jun 18 21:59:05] C has no builtin exponentiation operator
562 <seidos> [Jun 18 21:59:07] oh, power
563 <bgs100> [Jun 18 21:59:11] seidos, The C standard for function for exponentiation
564 <bgs100> [Jun 18 21:59:34] After changing the "(long)" to "(long long int)", the last line becomes:
565 <bgs100> [Jun 18 21:59:35] 2 to the power of 333: 9223372036854775807
566 <Snova> [Jun 18 21:59:38] also, I suspect the reason sin(42) returns such an odd number is that is expects radians
567 <Snova> [Jun 18 22:00:01] if you convert 42 to radians first, you get 0.67
568 <pedro3005> [Jun 18 22:00:06] oh yeah, maybe it is in radians
569 <pedro3005> [Jun 18 22:01:01] bgs100, well, math isn't difficult, most of what we need can be solved by a quick google
570 <bgs100> [Jun 18 22:01:09] Yes,
571 <pedro3005> [Jun 18 22:01:17] no real need to go over it in class
572 <seidos> [Jun 18 22:01:26] I like it
573 <seidos> [Jun 18 22:01:33] :(
574 <pedro3005> [Jun 18 22:01:42] ok sorry seidos :p
575 <bgs100> [Jun 18 22:01:48] but I would think it to be much easier to use a math function in your program than to connect to the net and retrieve and parse a page from Google in your program ;)
576 <seidos> [Jun 18 22:01:51] it's cool, it's the teacher's class
577 <seidos> [Jun 18 22:01:59] I just wouldn't go over this math stuff otherwise
578 <seidos> [Jun 18 22:02:05] I mean when do I ever use logs?
579 <seidos> [Jun 18 22:02:14] or even trig functions
580 <bgs100> [Jun 18 22:02:19] seidos,
581 <Snova> [Jun 18 22:02:27] whenever you feel the need to invert a power, and whenever you need to do something fancy with triangles/circles, I guess
582 <bgs100> [Jun 18 22:02:32] You use logs when you want to find how many bits would be needed to represent a google
583 <bgs100> [Jun 18 22:02:39] googol*
584 <bgs100> [Jun 18 22:02:53] Stupid company names :p
585 <seidos> [Jun 18 22:03:06] my point is, outside of this class, I have no problems to work on
586 <Snova> [Jun 18 22:03:10] I recall they named it after "a common misspelling of the word googol"
587 <bgs100> [Jun 18 22:03:30] Now it's a more common misspelling.
588 <Snova> [Jun 18 22:03:34] indeed
589 <seidos> [Jun 18 22:03:44] I almost mispelled it
590 <bgs100> [Jun 18 22:03:57] Changing (long long int) to (long double) changes the final line:
591 <bgs100> [Jun 18 22:03:57] 2 to the power of 333: 1.7498e+100
592 <seidos> [Jun 18 22:04:03] I need to improve my memory
593 <bgs100> [Jun 18 22:04:19] seidos, But you misspelled misspelled instead :p
594 <seidos> [Jun 18 22:04:38] bgs100, no I recalled googol was the proper spelling, right?
595 <bgs100> [Jun 18 22:04:42] seidos, no,
596 <seidos> [Jun 18 22:04:46] ah crap
597 <seidos> [Jun 18 22:04:50] lol
598 <pedro3005> [Jun 18 22:04:53] seidos, you're just so impatient for practicalities
599 <bgs100> [Jun 18 22:05:02] I'm saying instead you misspelled 'misspelled' as 'mispelled' xP
600 <bgs100> [Jun 18 22:05:27] ANYWAY
601 <bgs100> [Jun 18 22:05:30] ON WITH THE C
602 <pedro3005> [Jun 18 22:05:35] I mean, it's a long way until programming something useful
603 <seidos> [Jun 18 22:05:39] you make no sense, sir
604 <seidos> [Jun 18 22:05:44] on with the C
605 <bgs100> [Jun 18 22:05:48] seidos, <seidos> I almost mispelled it
606 <bgs100> [Jun 18 22:05:59] You misspelled the word "misspelled".
607 <seidos> [Jun 18 22:06:06] ohhhhh
608 <bgs100> [Jun 18 22:06:09] Lol.
609 <seidos> [Jun 18 22:06:17] didn't even know I was misspelling the word misspelled
610 <seidos> [Jun 18 22:06:24] I should pay more attention to the spell checker
611 <bgs100> [Jun 18 22:06:30] ANYWAY
612 <bgs100> [Jun 18 22:06:32] ON WITH THE C
613 <seidos> [Jun 18 22:06:32] I am too arrogant in my spelling habits
614 <seidos> [Jun 18 22:06:34] sorry
615 <bgs100> [Jun 18 22:06:41] np :p
616 <seidos> [Jun 18 22:06:43] *ability rather
617 <bgs100> [Jun 18 22:06:44] ON WITH THE C
618 <pedro3005> [Jun 18 22:06:49] go on
619 <bgs100> [Jun 18 22:06:59] ONWARDS, TO STDLIB.H
620 <seidos> [Jun 18 22:07:12] wait!
621 <seidos> [Jun 18 22:07:15] one question
622 <seidos> [Jun 18 22:07:20] how did you change the last line
623 <bgs100> [Jun 18 22:07:20] Everyone put on your war helmets, we-
624 <bgs100> [Jun 18 22:07:22] what
625 <seidos> [Jun 18 22:07:25] for pow
626 <seidos> [Jun 18 22:07:30] to long double?
627 <bgs100> [Jun 18 22:07:34] printf("2 to the power of 333: %Lg\n", (long double)pow(2, 333));
628 <pedro3005> [Jun 18 22:07:56] not Ld?
629 <bgs100> [Jun 18 22:08:00] No
630 <pedro3005> [Jun 18 22:08:11] oh right
631 <pedro3005> [Jun 18 22:08:13] okay
632 <pedro3005> [Jun 18 22:08:14] on with the C
633 <bgs100> [Jun 18 22:08:16] ld is long int, lld is long long int,
634 <bgs100> [Jun 18 22:08:22] and then you need long double
635 <bgs100> [Jun 18 22:08:25] SO YEAH
636 <bgs100> [Jun 18 22:08:29] WITH THE C
637 <bgs100> [Jun 18 22:08:31] ONWARDS
638 <seidos> [Jun 18 22:08:37] I get a warning with that
639 <bgs100> [Jun 18 22:08:42] Everyone put on your war helmets, we're hea-
640 <bgs100> [Jun 18 22:08:44] what
641 <seidos> [Jun 18 22:08:47] and it evaluates to 0
642 <bgs100> [Jun 18 22:08:53] ...
643 <Snova> [Jun 18 22:08:59] heehe
644 <bgs100> [Jun 18 22:08:59] It works fine here, so...
645 <Snova> [Jun 18 22:09:05] ONWARDS
646 <seidos> [Jun 18 22:09:05] printf("2 to the power of 333: %ld\n", (long double)pow(2, 333));
647 <bgs100> [Jun 18 22:09:11] Snova, VERILY!!!
648 <seidos> [Jun 18 22:09:13] all right, onwards
649 <Snova> [Jun 18 22:09:17] seidos: ld is long int
650 <bgs100> [Jun 18 22:09:18] seidos, NO
651 <bgs100> [Jun 18 22:09:22] seidos, Lg, not ld
652 <bgs100> [Jun 18 22:09:29] printf("2 to the power of 333: %Lg\n", (long double)pow(2, 333)); [Jun 18 22:09:29]
653 <bgs100> [Jun 18 22:09:39] ...
654 <bgs100> [Jun 18 22:09:41] onwards?
655 <Snova> [Jun 18 22:09:46] seidos: there's about a million formatters for printf; install manpages-dev and see "man 3 printf" if you want to bore yourself
656 <pedro3005> [Jun 18 22:09:46] yes please
657 <Snova> [Jun 18 22:09:49] bgs100: hey, this is C
658 <bgs100> [Jun 18 22:09:57] Snova, hm?
659 <seidos> [Jun 18 22:10:01] onwards
660 <bgs100> [Jun 18 22:10:11] ONWARDS, TO STDLIB.H
661 <Snova> [Jun 18 22:10:12] bgs100: this is C, we're just on stdio.h rather than stdlib.h :p
662 <bgs100> [Jun 18 22:10:20] Everyone put on your war helmets, we're heading-
663 <Snova> [Jun 18 22:10:25] and there's about a million things there
664 <bgs100> [Jun 18 22:10:41] interrupted again... xP
665 <bgs100> [Jun 18 22:10:49] Snova, More file processing is later
666 <pedro3005> [Jun 18 22:10:56] ===== stdlib.h ======
667 <bgs100> [Jun 18 22:10:58] and such
668 <pedro3005> [Jun 18 22:11:00] go on
669 <bgs100> [Jun 18 22:11:02] pedro3005, thanks
670 <bgs100> [Jun 18 22:11:05] ONWARDS, TO STDLIB.H
671 <bgs100> [Jun 18 22:11:25] Everyone put on your war helmets, we're heading into m/c/realloc()/free() territory!
672 <bgs100> [Jun 18 22:11:30] :p
673 <Snova> [Jun 18 22:11:35] hope you've explained pointers
674 <bgs100> [Jun 18 22:11:44] Yep
675 <Snova> [Jun 18 22:11:46] if not, prepare for a lot more than you bargained for, because that's never come very easily
676 <Snova> [Jun 18 22:11:49] oh good
677 <bgs100> [Jun 18 22:11:58] We're going a bit deeper in this time.
678 * seidos [Jun 18 22:12:00] hopes he remembers his explanation
679 * bgs100 [Jun 18 22:12:10] hopes so too.
680 * bgs100 [Jun 18 22:12:20] equips war helmet
681 <seidos> [Jun 18 22:12:20] I don't think any amount of body armor is going to help
682 <Snova> [Jun 18 22:12:28] well, free() is when mr. tycoon evicts people... ^_^
683 <bgs100> [Jun 18 22:12:33] Good point...
684 <bgs100> [Jun 18 22:12:36] Snova, LOL.
685 <seidos> [Jun 18 22:13:05] pedro3005, did you get that one?
686 <bgs100> [Jun 18 22:13:06] seidos, Correct, the pointers know you're exact location, inside all of your body armour...
687 <pedro3005> [Jun 18 22:13:15] seidos, nope...
688 <pedro3005> [Jun 18 22:13:19] must be a programmer's joke
689 <seidos> [Jun 18 22:13:25] all right, I'm not totally doomed
690 <bgs100> [Jun 18 22:13:33] pshaw, you guys are programmers
691 * bgs100 [Jun 18 22:13:41] gives you both official badges
692 <Snova> [Jun 18 22:13:45] long story; I didn't expect anyone but bgs100 to get that one :p
693 <bgs100> [Jun 18 22:14:01] wait I was supposed to get it?
694 <bgs100> [Jun 18 22:14:10] (just kidding)
695 <Snova> [Jun 18 22:14:27] and if you ask what the story is I'm going to put on my drill sargeant hat and yell at you
696 <pedro3005> [Jun 18 22:14:40] onwards to STDLIB.H
697 <bgs100> [Jun 18 22:14:46] okay coo, then
698 <bgs100> [Jun 18 22:14:49] cpp;*
699 <bgs100> [Jun 18 22:14:51] cool*
700 <bgs100> [Jun 18 22:14:54] STUPID KEYBOARD
701 <bgs100> [Jun 18 22:15:04] anyway
702 <pedro3005> [Jun 18 22:15:05] cpp? I thought this was C
703 <pedro3005> [Jun 18 22:15:07] :P
704 <bgs100> [Jun 18 22:15:09] brb, making example
705 <bgs100> [Jun 18 22:15:14] pedro3005, lol, nice.
706 <bgs100> [Jun 18 22:21:02] http://pastebin.com/iPtxQJVn
707 <bgs100> [Jun 18 22:21:05] SCRO
708 <bgs100> [Jun 18 22:21:12] pedro3005, seidos ^
709 <seidos> [Jun 18 22:21:48] bgs100, what's a good name for this file?
710 <bgs100> [Jun 18 22:21:56] 9.c ?
711 <bgs100> [Jun 18 22:21:57] :p
712 <seidos> [Jun 18 22:21:59] stdlib sounds good
713 <bgs100> [Jun 18 22:22:14] seidos, malloc would be good too.
714 <seidos> [Jun 18 22:22:15] I want to be able to reference them later, when I *know* I forget stuff
715 <seidos> [Jun 18 22:23:04] -lm flag for compiler still?
716 <Snova> [Jun 18 22:23:24] no
717 <pedro3005> [Jun 18 22:23:29] sizeof(int)?
718 <Snova> [Jun 18 22:23:32] -lm links in the math library, which is separate for some stupid reason
719 * pedro3005 [Jun 18 22:23:33] dies
720 <Snova> [Jun 18 22:23:36] we're not using it right now
721 <Snova> [Jun 18 22:23:47] pedro3005: it will return 4, if that explains anything
722 <seidos> [Jun 18 22:23:52] it still worked, but I'll recompile
723 <bgs100> [Jun 18 22:23:54] pedro3005, Lol.
724 <Snova> [Jun 18 22:23:57] seidos: either way
725 <bgs100> [Jun 18 22:24:02] pedro3005, All shall be explained
726 <bgs100> [Jun 18 22:24:07] Well
727 <bgs100> [Jun 18 22:24:09] Maybe not all
728 <seidos> [Jun 18 22:24:26] 0 for starters, then 42
729 <bgs100> [Jun 18 22:24:26] But close enough for now.
730 <Snova> [Jun 18 22:24:32] "and that concludes today's lessons; the remaining mysteries I leave as homework"?
731 <bgs100> [Jun 18 22:24:38] Snova, xD
732 <pedro3005> [Jun 18 22:25:08] bgs100, be sure to assign some homework
733 <pedro3005> [Jun 18 22:25:16] was it you that explained structs?
734 <pedro3005> [Jun 18 22:25:27] I don't remember it very well
735 <bgs100> [Jun 18 22:25:30] I did yesterday.
736 <bgs100> [Jun 18 22:25:35] xd
737 <pedro3005> [Jun 18 22:25:36] ok go on with malloc
738 <seidos> [Jun 18 22:25:56] me neither
739 <bgs100> [Jun 18 22:25:57] Snova, I imagine a C language teacher coming into a class, writing the classic hello world on the board, and then saying "This concludes the class, your homework is to learn the rest of C."
740 <bgs100> [Jun 18 22:26:20] Okay
741 <bgs100> [Jun 18 22:26:21] So
742 <bgs100> [Jun 18 22:26:36] First, sizeof
743 <pedro3005> [Jun 18 22:26:52] oh that one is easy
744 <pedro3005> [Jun 18 22:27:00] it's the size of something
745 <pedro3005> [Jun 18 22:27:02] :P
746 <Snova> [Jun 18 22:27:06] in bytes, to be exact
747 <bgs100> [Jun 18 22:27:14] <look of dissapproval>
748 <bgs100> [Jun 18 22:27:27] I'm going to continue with what I was saying anyway
749 <Snova> [Jun 18 22:27:37] s/ss/s/
750 <bgs100> [Jun 18 22:27:37] sizeof (in the way we're using it) will tell you the number of bytes in a datatype.
751 <bgs100> [Jun 18 22:27:43] Snova, Yes, i know
752 <bgs100> [Jun 18 22:27:45] I*
753 <bgs100> [Jun 18 22:28:19] sizeof(int) varies depending on the system.
754 <Snova> [Jun 18 22:28:36] officially; you're pretty much going to get 4 anywhere you go
755 <bgs100> [Jun 18 22:28:43] sizeof most stuff varies depending on the system, except for sizeof(char)
756 <bgs100> [Jun 18 22:28:51] Snova, sssh
757 <bgs100> [Jun 18 22:29:06] A char is always one byte.
758 <bgs100> [Jun 18 22:29:08] So yeah
759 <bgs100> [Jun 18 22:29:18] Then, we get to malloc
760 <bgs100> [Jun 18 22:29:30] Does anyone here (BESIDES SNOVA) know what it stands for?
761 <seidos> [Jun 18 22:29:40] m-allocation?
762 <pedro3005> [Jun 18 22:29:52] master allocation
763 <pedro3005> [Jun 18 22:29:55] meta allocation
764 <bgs100> [Jun 18 22:29:57] seidos, You have allocation correct,
765 <Snova> [Jun 18 22:29:59] seidos: close, but this isn't string theory
766 <bgs100> [Jun 18 22:30:00] what about the m?
767 <bgs100> [Jun 18 22:30:06] Snova, lol
768 <seidos> [Jun 18 22:30:13] haha
769 <bgs100> [Jun 18 22:30:14] pedro3005, fail and fail
770 <pedro3005> [Jun 18 22:30:28] mister allocation
771 <pedro3005> [Jun 18 22:30:30] he is grumpy
772 <bgs100> [Jun 18 22:30:36] Lol.
773 <bgs100> [Jun 18 22:30:37] No.
774 <seidos> [Jun 18 22:30:43] multi?
775 <bgs100> [Jun 18 22:30:47] It stands for... (calls on Snova)
776 <Snova> [Jun 18 22:30:54] MAGGOTS
777 <bgs100> [Jun 18 22:30:57] XD
778 <Snova> [Jun 18 22:31:09] memory
779 <pedro3005> [Jun 18 22:31:09] memory!
780 <pedro3005> [Jun 18 22:31:10] :D
781 <bgs100> [Jun 18 22:31:15] Lol.
782 <pedro3005> [Jun 18 22:31:17] ok I googled it
783 <bgs100> [Jun 18 22:31:22] Man
784 * seidos [Jun 18 22:31:24] bangs his head and chants stupid
785 <bgs100> [Jun 18 22:31:27] I was about to give you a star
786 <bgs100> [Jun 18 22:31:35] seidos, pedro googled it :p
787 <bgs100> [Jun 18 22:31:47] At least you didn't cheat
788 <seidos> [Jun 18 22:31:50] that's a good idea, I have too many tabs open already
789 <bgs100> [Jun 18 22:31:59] HEY
790 <bgs100> [Jun 18 22:32:01] BAD IDEA
791 <bgs100> [Jun 18 22:32:05] IT'S CHEATING
792 <bgs100> [Jun 18 22:32:12] :p
793 <bgs100> [Jun 18 22:32:14] Okay
794 <bgs100> [Jun 18 22:32:20] So what this does is
795 <bgs100> [Jun 18 22:32:31] clear up 4 bytes of space in your memory.
796 <pedro3005> [Jun 18 22:32:46] why 4?
797 <bgs100> [Jun 18 22:32:46] And then it gives freaky_pointer the address of the start of these
798 <Snova> [Jun 18 22:32:51] pedro3005: the size of an int
799 <bgs100> [Jun 18 22:32:55] pedro3005, That's how many bytes are in an int
800 <bgs100> [Jun 18 22:32:58] Darn it
801 <bgs100> [Jun 18 22:33:00] Beaten
802 <pedro3005> [Jun 18 22:33:02] oh cool
803 <bgs100> [Jun 18 22:33:15] pedro3005, Yeah, that's why we have sizeof(int) there.
804 <Snova> [Jun 18 22:33:18] pedro3005: malloc() allocates a certain number of bytes; allocating sizeof(int) means... ?
805 <pedro3005> [Jun 18 22:33:32] allocating an int
806 <seidos> [Jun 18 22:33:36] malloc(4)
807 * bgs100 [Jun 18 22:33:37] claps
808 * bgs100 [Jun 18 22:33:44] gives pedro3005 a star
809 * bgs100 [Jun 18 22:33:48] gives seidos a star
810 * bgs100 [Jun 18 22:33:54] gives Snova a star
811 * bgs100 [Jun 18 22:34:01] gives bgs100 a star
812 * bgs100 [Jun 18 22:34:06] gives bgs100 5 stars
813 <bgs100> [Jun 18 22:34:10] Anyway
814 <seidos> [Jun 18 22:34:20] what does the * in *freaky_pointer do?
815 <bgs100> [Jun 18 22:34:20] Now that we are all shiny.
816 <bgs100> [Jun 18 22:34:32] seidos, Gets the value at the address freaky_pointer holds
817 <Snova> [Jun 18 22:34:37] seidos: obtains the value that the pointer is pointing to, in this case an int
818 <Snova> [Jun 18 22:34:45] either that or is used to set it; same idea
819 <seidos> [Jun 18 22:34:55] weird
820 <bgs100> [Jun 18 22:35:07] You said it made sense, yesterday :P
821 <bgs100> [Jun 18 22:35:15] anyway
822 <bgs100> [Jun 18 22:35:17] So
823 <bgs100> [Jun 18 22:35:42] We pretty much just manually (sort of) created a integer
824 * bgs100 [Jun 18 22:35:55] creates another example
825 <pedro3005> [Jun 18 22:37:02] why is malloc needed?
826 <Snova> [Jun 18 22:37:29] it's not, and there's no reason to allocate one int with it
827 <Snova> [Jun 18 22:37:36] usually
828 <pedro3005> [Jun 18 22:37:43] ever?
829 <pedro3005> [Jun 18 22:37:59] in which case would malloc be useful?
830 <seidos> [Jun 18 22:38:04] no wonder we need a war helmet
831 <Snova> [Jun 18 22:38:18] larger allocations, and passing memory up the stack
832 <Snova> [Jun 18 22:38:24] +without globals
833 <bgs100> [Jun 18 22:38:25] pedro3005, Many cases
834 <bgs100> [Jun 18 22:38:32] we will get to those later
835 <Snova> [Jun 18 22:38:35] also, dynamic allocations; most major reason
836 <bgs100> [Jun 18 22:38:36] Here is the example:
837 <bgs100> [Jun 18 22:38:43] Snova, yeah
838 <bgs100> [Jun 18 22:38:53] s/yeah/+1/
839 <bgs100> [Jun 18 22:39:13] http://pastebin.com/RadyCQLg
840 <bgs100> [Jun 18 22:39:17] SCRO
841 <bgs100> [Jun 18 22:39:24] pedro3005, seidos ^
842 <bgs100> [Jun 18 22:39:44] Also, might want to open a memory usage monitor
843 <pedro3005> [Jun 18 22:40:10] I killed it
844 <bgs100> [Jun 18 22:40:17] Good.
845 <bgs100> [Jun 18 22:40:26] seidos ?
846 <bgs100> [Jun 18 22:40:52] ...
847 <seidos> [Jun 18 22:40:59] I took a little while to kill it
848 <bgs100> [Jun 18 22:41:02] Ah
849 <bgs100> [Jun 18 22:41:04] Good
850 <bgs100> [Jun 18 22:41:09] Anyway
851 <seidos> [Jun 18 22:41:20] after killing it, is memory freed?
852 <bgs100> [Jun 18 22:41:28] The point of this was to demonstrate the dangers of m/a/realloc()
853 <bgs100> [Jun 18 22:41:30] seidos, Yes
854 <bgs100> [Jun 18 22:41:46] This is known as a "memory leak"
855 <seidos> [Jun 18 22:42:16] hmmm
856 <bgs100> [Jun 18 22:42:18] It is when something is malloc'ed, but forgotten about later in the program, so it just sits around, hogging up your memory.
857 <bgs100> [Jun 18 22:42:29] (or calloc/realloc'd)
858 <bgs100> [Jun 18 22:42:36] I'll just say alloc'd
859 <seidos> [Jun 18 22:42:48] is it possible for memory leaks to exist in some other way?
860 <bgs100> [Jun 18 22:43:05] Yes, most programs don't have memory sucking loops in them
861 <bgs100> [Jun 18 22:43:18] If a variable is assigned to a malloc,
862 <bgs100> [Jun 18 22:43:24] in a non-main function,
863 <bgs100> [Jun 18 22:43:35] and that memory is not somehow free'd later,
864 <bgs100> [Jun 18 22:43:49] (e.g. the function returned the address and another function free'd it),
865 <bgs100> [Jun 18 22:44:00] it will just be sitting there until the program ends
866 <bgs100> [Jun 18 22:44:45] This was a very extreme example.
867 <bgs100> [Jun 18 22:45:05] Anyway
868 <bgs100> [Jun 18 22:45:25] It's 10:41 here; think you've had enough C/Python/Math lesson for the day?
869 <seidos> [Jun 18 22:45:50] I could probably keep going actually
870 <bgs100> [Jun 18 22:45:55] hmm
871 <bgs100> [Jun 18 22:45:57] pedro3005 ?
872 <pedro3005> [Jun 18 22:46:27] bgs100, I'm actually craving sleep, but I'm sure you could continue with seidos
873 <seidos> [Jun 18 22:46:39] it's up to you dude
874 <Snova> [Jun 18 22:47:04] seidos: "memory leak" just means allocating something without ever deallocating it
875 <Snova> [Jun 18 22:47:14] by accident, that is
876 <bgs100> [Jun 18 22:47:18] Lol
877 <bgs100> [Jun 18 22:47:25] pedro3005, Okay, bye
878 <bgs100> [Jun 18 22:47:28] Hm
879 <bgs100> [Jun 18 22:47:29] Wait
880 <bgs100> [Jun 18 22:47:31] Homework
881 <seidos> [Jun 18 22:47:45] Snova, when I heard "memory leak" I think of a continues leaking of memory, does it have to be continuous to be a "leak"?
882 <Snova> [Jun 18 22:47:51] seidos: nah
883 <pedro3005> [Jun 18 22:48:02] Night
884 <bgs100> [Jun 18 22:48:08] pedro3005, Wait!
885 * bgs100 [Jun 18 22:48:14] has to think of homework
886 <bgs100> [Jun 18 22:48:33] Hm, I know
887 <bgs100> [Jun 18 22:48:37] pedro3005, seidos
888 <bgs100> [Jun 18 22:48:55] I want you to take your program from the previous homework,
889 <bgs100> [Jun 18 22:49:40] and modify it so that you never declare an int; doing it all with int pointers + malloc.
890 <seidos> [Jun 18 22:49:55] Jesus!
891 * bgs100 [Jun 18 22:49:58] will have to think of better homework in advance for tommorow :p
892 <bgs100> [Jun 18 22:50:07] seidos, It's not that bad xP
893 <bgs100> [Jun 18 22:50:32] pedro3005, okay?
894 * bgs100 [Jun 18 22:50:42] hopes pedro3005 isn't gone yet :p
895
learners/18062010 (last edited 2010-06-20 04:25:52 by 117)