Jun 29 22:45:51 <-- CLASS STARTED --> Jun 29 22:46:04 * kushal has changed the topic to: Welcome to Linux User's Group of Durgapur | Mailing list at http://lists.dgplug.org/listinfo.cgi/users-dgplualso jg.org | How to write "Hello World!" in gcc http://tv.dgplug.org/ | Old classes http://www.dgplug.org/irclogs/ | Tonight 7pm Vi by Kushal, 10:30pm gcc by __pjp__, 12:00AM shell by rishi | <--CLASS STARTED--> Jun 29 22:46:12 _pjp_, all yours Jun 29 22:46:25 <_pjp_> kushal: yes, thanks. Jun 29 22:46:45 <_pjp_> hello guys Jun 29 22:46:48 * nandy_lost (n=chatzill@59.178.175.199) has joined #dgplug Jun 29 22:46:48 * techno_freak welcomes the most happening bachelor in bengaluru Jun 29 22:46:59 hello Jun 29 22:47:01 techno_freak, shhhhh! class is going on Jun 29 22:47:04 Hello Jun 29 22:47:05 hi. Jun 29 22:47:19 <_pjp_> I assume everybody here know how to edit a file, and write a C program. Jun 29 22:47:25 * ecntrk1 (i=sunny@117.194.0.243) has joined #dgplug Jun 29 22:47:34 _pjp_, no :| Jun 29 22:47:38 techno_freak, please Jun 29 22:47:44 <_pjp_> techno_freak: hi Jun 29 22:47:59 kushal, err.. i donno the second part, let him tell Jun 29 22:48:06 ! Jun 29 22:48:14 ecntrk, yes Jun 29 22:48:31 i got disconnected.. Jun 29 22:48:39 nothing happened Jun 29 22:48:42 is it the 1st class? Jun 29 22:48:51 ecntrk, and from now on please ask friends in pm Jun 29 22:49:00 _pjp_, please carry on Jun 29 22:49:11 Jun 29 22:49:26 <_pjp_> so for example, let's write the program to print the greeting "hello, world\n" and I'll explain how to compile it, and other things related. Jun 29 22:49:39 <_pjp_> techno_freak: ? Jun 29 22:49:48 _pjp_, carry on Jun 29 22:51:03 * ecntrk has quit (Read error: 110 (Connection timed out)) Jun 29 22:52:25 <_pjp_> does everyone have the program ready? Jun 29 22:52:27 * debayan (n=debayan@117.198.32.77) has joined #dgplug Jun 29 22:52:30 <_pjp_> see: http://rafb.net/p/2t460H47.html Jun 29 22:52:33 I have... Jun 29 22:52:44 <_pjp_> Great! Jun 29 22:53:12 but.. I'm not in linux.. so in notepad...:( Jun 29 22:53:13 done Jun 29 22:53:20 ecntrk1, DON"T SPEAK Jun 29 22:53:23 ecntrk1, use ! Jun 29 22:53:23 _pjp_, ya ready Jun 29 22:53:46 !sure...sorry... Jun 29 22:53:51 <_pjp_> ecntrk1: you need the Linux terminal Jun 29 22:53:55 * Debashree_ (n=Debashre@61.2.164.146) has joined #dgplug Jun 29 22:53:56 _pjp_, yes ready Jun 29 22:54:10 done Jun 29 22:54:20 done Jun 29 22:54:22 ! Jun 29 22:54:24 done Jun 29 22:54:33 done Jun 29 22:54:34 <_pjp_> Now on the shell prompt type: $ gcc hello.c Jun 29 22:54:44 <_pjp_> you can even say: cc hello.c Jun 29 22:54:52 <_pjp_> I assume your filename is hello.c Jun 29 22:55:20 done Jun 29 22:55:30 ! Jun 29 22:55:30 ! Jun 29 22:55:45 <_pjp_> Any error..anybody? Jun 29 22:55:55 susenj, yes Jun 29 22:55:56 <_pjp_> ecntrk1: susenj? Jun 29 22:56:03 but first, don't we need to install gcc? I don't have it installed in my distro.. Jun 29 22:56:08 i tried cc in place of gcc ,it's okay!but when i typed man cc,shows no manual entry for cc Jun 29 22:56:18 * Debashree has quit (Nick collision from services.) Jun 29 22:56:24 Jun 29 22:56:29 Jun 29 22:56:29 _pjp_, it has returned to $ prompt Jun 29 22:56:29 * Debashree_ is now known as Debashree Jun 29 22:56:37 _pjp_, no error Jun 29 22:56:47 _pjp_, that means no error?? Jun 29 22:56:50 done _pjp_ Jun 29 22:56:53 <_pjp_> susenj: cc is a symbolic link to gcc Jun 29 22:57:05 ya arpita Jun 29 22:57:13 ria, o.k Jun 29 22:57:15 <_pjp_> susenj: do you know about symbolic link? Jun 29 22:57:21 is it not a command? Jun 29 22:57:21 all others STOP TALKING Jun 29 22:57:25 arpita, no, do ls and check if you have a.out Jun 29 22:57:37 STOP TALKING Jun 29 22:57:43 no,please let me know Jun 29 22:57:51 <_pjp_> If you did not see any errors, you should see a file called a.out Jun 29 22:58:00 <_pjp_> is it there? Jun 29 22:58:11 yup Jun 29 22:58:19 _pjp_, yes a.out is there Jun 29 22:58:49 >techno_freak< that was for the students Jun 29 22:58:50 <_pjp_> susenj: symbolic link is like a desktop shortcut in Windows. Jun 29 22:59:14 <_pjp_> if you see the file a.out, on the shell prompt say $ ./a.out Jun 29 22:59:15 oh,i see,thanks! Jun 29 22:59:50 <_pjp_> that should display the greeting "Hello, world\n" Jun 29 22:59:57 _pjp_, done Jun 29 23:00:07 done Jun 29 23:00:09 working Jun 29 23:00:13 me too Jun 29 23:00:42 * rtnpro (n=rtnpro@121.241.211.243) has joined #dgplug Jun 29 23:00:55 done Jun 29 23:01:04 done Jun 29 23:01:24 _pjp_:! Jun 29 23:01:26 <_pjp_> a.out is the earliest executable file format, and the name is the gift of Unix legacy. Jun 29 23:01:48 <_pjp_> though the executable file format today in Linux is far different. Jun 29 23:01:51 <_pjp_> see: http://en.wikipedia.org/wiki/A.out Jun 29 23:03:32 * techno_freak has quit ("Leaving") Jun 29 23:04:39 <_pjp_> Now when you said $ gcc hello.c, it took four steps for gcc to actually generate the executable/binary file a.out. Jun 29 23:05:19 <_pjp_> fours steps are: Preprocessing, Compilation, Assembly, and lastly Code generation. Jun 29 23:05:44 * coolpyro_rishi (n=chatzill@202.63.119.36) has joined #dgplug Jun 29 23:05:59 <_pjp_> I hope folks are aware of these steps. Jun 29 23:06:14 <_pjp_> deepak: ? Jun 29 23:06:16 ! Jun 29 23:06:20 <_pjp_> roni: ? Jun 29 23:06:25 [aritra@desktop ~]$ ./a.out Jun 29 23:06:25 Hello, world Jun 29 23:06:25 [aritra@desktop ~]$ gcc hello.c Jun 29 23:06:25 hello.c:9:2: warning: no newline at end of file Jun 29 23:06:46 roni, please use http://rafb.net/paste from now on Jun 29 23:06:47 why this is shown Jun 29 23:06:52 guys all please Jun 29 23:07:10 USE http://rffb.net/paste for showing any code or error Jun 29 23:07:11 <_pjp_> roni: did you copy file from Windows to Linux? Jun 29 23:07:18 roni, see written in english Jun 29 23:07:27 _pjp_:tell me the option i can use with gcc to name the file i wish Jun 29 23:07:46 <_pjp_> deepak: you mean instead of a.out? Jun 29 23:08:11 kushal, the link is http://rafb.net/paste Jun 29 23:08:16 _pjp_:yes Jun 29 23:08:22 Soumya, correct , my typo Jun 29 23:08:45 deepak, use ! to ask permission for speaking Jun 29 23:08:55 <_pjp_> Okay, to name the executable file say: $ gcc -o hello.c Jun 29 23:09:08 * mobilesuit (n=freedom@59.93.217.29) has joined #dgplug Jun 29 23:09:16 <_pjp_> Or $ cc -o hello.c Jun 29 23:09:35 * kushal gives channel operator status to _pjp_ Jun 29 23:09:53 * mobilesuit is away: Jun 29 23:09:53 <_pjp_> the -o option of gcc/cc lets you specify the output file-name. Jun 29 23:10:05 <_pjp_> see gcc --help | more for more options. Jun 29 23:10:30 _pjp_:ok thanks Jun 29 23:10:45 <_pjp_> You can actually see the output of every step mentioned earlier. Jun 29 23:10:54 ! Jun 29 23:11:02 <_pjp_> rtnpro: ? Jun 29 23:11:15 whats cc -o? Jun 29 23:11:15 * ecntrk1 has quit () Jun 29 23:11:51 <_pjp_> cc is symbolic link/shorcut to gcc, it works the same way. Jun 29 23:12:06 ! Jun 29 23:12:23 means in place of gcc...can I use cc? Jun 29 23:12:31 _pjp_:! Jun 29 23:12:46 <_pjp_> the earliest Unix compiler was called cc, for C Compiler Jun 29 23:12:50 <_pjp_> rtnpro: yes Jun 29 23:13:02 ok Jun 29 23:13:04 <_pjp_> and the GNU version of cc was called gcc. Jun 29 23:13:38 _pjp_, please carry on Jun 29 23:13:38 <_pjp_> I hope all are aware of GNU Jun 29 23:13:50 we will take questions later Jun 29 23:13:54 <_pjp_> kushal: yes. Jun 29 23:13:55 ok Jun 29 23:14:47 <_pjp_> So far, everybody with me? Jun 29 23:14:53 yes Jun 29 23:15:14 yup Jun 29 23:15:21 ya Jun 29 23:15:25 _pjp_:yes Jun 29 23:15:27 yes Jun 29 23:15:30 _pjp_: yes Jun 29 23:15:35 yes Jun 29 23:15:43 yea Jun 29 23:15:43 yes Jun 29 23:15:54 <_pjp_> Great. Jun 29 23:15:59 yes Jun 29 23:16:16 * atanubera (n=root@125.20.11.34) has joined #dgplug Jun 29 23:16:31 yes Jun 29 23:16:35 yes Jun 29 23:16:48 * a (i=a@117.201.96.63) has joined #dgplug Jun 29 23:16:53 <_pjp_> Now let's see how to generate a.out in two steps Jun 29 23:17:41 <_pjp_> please type: gcc -c hello.c Jun 29 23:17:47 <_pjp_> or cc -c hello.c Jun 29 23:18:31 <_pjp_> the option `-c' stops just after compilation, that is after creating the object code. Jun 29 23:18:57 <_pjp_> that means, preprocessing->compilation Jun 29 23:19:20 ! Jun 29 23:19:29 <_pjp_> what remains is linking->executable_code_generation Jun 29 23:19:32 <_pjp_> nandy_lost: ? Jun 29 23:19:48 after compiling file name is hel.o Jun 29 23:19:49 * debayan has quit (Read error: 110 (Connection timed out)) Jun 29 23:19:56 how can we open it/ Jun 29 23:19:59 ? Jun 29 23:20:35 * Soumya_ (n=Soumya@59.164.98.92) has joined #dgplug Jun 29 23:20:47 <_pjp_> nandy_lost: you don't have to open it, it's not in human readable format Jun 29 23:20:59 * Soumya has quit (Nick collision from services.) Jun 29 23:21:05 * Soumya_ is now known as Soumya Jun 29 23:21:07 is it executable code? Jun 29 23:21:17 Jun 29 23:21:19 <_pjp_> nandy_lost: file-name remains same, except extension changes to .o Jun 29 23:21:38 nandy_lost, please ask questions later Jun 29 23:21:48 it gives some garbage with "hello world!" in the end,when i typed cat hello.o Jun 29 23:21:51 <_pjp_> nandy_lost: not executable really, but it's in binary format. Jun 29 23:22:37 please move forward Jun 29 23:22:48 So todays topic is C programming in gcc compiler Jun 29 23:23:15 I am following the process Jun 29 23:23:27 i don't think you need to re-iterate the topic Jun 29 23:23:37 <_pjp_> susenj: right, the garbage is actually the information used by the gcc. Jun 29 23:23:44 * root (n=root@117.194.2.152) has joined #dgplug Jun 29 23:24:01 * root is now known as Guest29576 Jun 29 23:24:12 <_pjp_> atanubera: C Programming *using* gcc compiler Jun 29 23:24:24 * kart_ has quit (Read error: 104 (Connection reset by peer)) Jun 29 23:24:29 * kart__ (n=kart_@121.245.17.223) has joined #dgplug Jun 29 23:24:35 <_pjp_> kart__: hi Jun 29 23:24:46 Hi .. sory i'm late Jun 29 23:24:46 * kart__ is now known as kart_ Jun 29 23:25:01 * Guest29576 is now known as t4num0y_cs3 Jun 29 23:25:24 <_pjp_> now let's see -c option in action. Jun 29 23:25:43 _pjp_: You are late ;) Jun 29 23:25:49 * rtnpro has quit ("Leaving") Jun 29 23:25:50 * ria_ (n=ria@219.64.69.160) has joined #dgplug Jun 29 23:26:08 * ria has quit (Nick collision from services.) Jun 29 23:26:21 * ria_ is now known as ria Jun 29 23:26:21 <_pjp_> kart_: yeah, was having dinner. :) Jun 29 23:26:43 _pjp_: :) Jun 29 23:26:53 >kart_< please talk in pm Jun 29 23:27:35 _pjp_:carry on Jun 29 23:27:38 <_pjp_> please modify the hello.c to also display square root of some number using maths library function: sqrt() Jun 29 23:28:51 * nandy_lost_ (n=chatzill@59.178.169.121) has joined #dgplug Jun 29 23:29:41 ! Jun 29 23:29:42 * chacha_chaudhry_ (n=dev@122.161.23.179) has joined #dgplug Jun 29 23:30:20 >arpita< arpita yes Jun 29 23:30:26 <_pjp_> see: http://rafb.net/p/6sIpnQ62.html Jun 29 23:30:50 <_pjp_> now, first say: gcc hello.c Jun 29 23:30:55 <_pjp_> or cc hello.c Jun 29 23:30:59 <_pjp_> what error do you get? Jun 29 23:31:06 * t4num0y_cs3 has quit ("leaving") Jun 29 23:32:04 * t4num0y_cs3 (n=Neo@117.194.2.152) has joined #dgplug Jun 29 23:32:29 * rishi (n=rishi@gnu-india/supporter/debarshi) has joined #dgplug Jun 29 23:32:40 please paste the error in the rafb.net/paste and give the link Jun 29 23:33:17 * Debashree has quit (Read error: 104 (Connection reset by peer)) Jun 29 23:33:30 * Prams (n=prams@125.20.11.34) has left #dgplug Jun 29 23:33:40 * suse_nj (n=root@59.178.169.121) has joined #dgplug Jun 29 23:33:41 <_pjp_> on some machines gcc might not complain Jun 29 23:33:56 <_pjp_> as maths library is linked by default. Jun 29 23:34:14 <_pjp_> ls Jun 29 23:34:26 <_pjp_> oops..sorry! Jun 29 23:34:45 my filename is 2nd.c error given is http://rafb.net/p/MWYHas92.html Jun 29 23:34:56 http://rafb.net/p/JtMVYv53.html Jun 29 23:35:03 the error ^^ Jun 29 23:35:30 <_pjp_> Excellent! :) Jun 29 23:36:14 http://rafb.net/p/2u54Mr27.html Jun 29 23:36:16 <_pjp_> the error says that the function sqrt() is not defined in the file hello.c Jun 29 23:36:32 mine is here: http://rafb.net/p/y0DFKl10.html Jun 29 23:36:36 * debayan (n=debayan@117.198.32.147) has joined #dgplug Jun 29 23:36:57 * Debashree (n=Debashre@61.2.164.51) has joined #dgplug Jun 29 23:36:59 <_pjp_> Great..all errors are same. Jun 29 23:37:14 http://rafb.net/p/dNaBbQ64.html Jun 29 23:37:29 error ^^^ Jun 29 23:37:30 my error is here :http://rafb.net/p/H0V47h97.html Jun 29 23:37:55 <_pjp_> so..the function sqrt () is defined in the standard maths library. Jun 29 23:38:09 <_pjp_> now type gcc -c hello.c Jun 29 23:38:14 <_pjp_> or cc -c hello.c Jun 29 23:38:43 done, no errors Jun 29 23:39:03 yup, next? Jun 29 23:39:48 _pjp_, my error ishttp://rafb.net/p/w2VNBw45.html Jun 29 23:39:51 * kart_ has quit (Read error: 104 (Connection reset by peer)) Jun 29 23:40:19 <_pjp_> right..option -c comes handy to point out compilation/syntax errors. Jun 29 23:40:27 <_pjp_> arpita: with -c option? Jun 29 23:40:39 * ria_ (n=ria@219.64.69.160) has joined #dgplug Jun 29 23:40:57 * ria has quit (Nick collision from services.) Jun 29 23:41:05 * ria_ is now known as ria Jun 29 23:41:32 _pjp_:done no error Jun 29 23:41:34 <_pjp_> because when you use gcc -c, the actual linking is deferred till later. Jun 29 23:41:44 _pjp_, with -c option it is not showing any errors Jun 29 23:41:47 ! Jun 29 23:41:56 <_pjp_> t4num0y_cs3: ? Jun 29 23:42:00 _pjp_, sorry for interruption, was disconnected Jun 29 23:42:02 <_pjp_> oops..sorry later Jun 29 23:42:06 <_pjp_> or cc -c hello.c Jun 29 23:42:12 <_pjp_> right Jun 29 23:42:14 can i get what is done after this? Jun 29 23:42:20 i don't understand the function of -c ? Jun 29 23:42:44 t4num0y_cs3, read gcc --help Jun 29 23:42:48 to suppress the errors t4num0y! Jun 29 23:42:52 _pjp_, carry on Jun 29 23:42:59 _pjp_, how come only gcc was showing errors and gcc -c is not showing errors?? Jun 29 23:43:15 * chacha_chaudhry has quit (Connection timed out) Jun 29 23:43:32 * chacha_chaudhry_ is now known as chacha_chaudhry Jun 29 23:44:09 * SDey has quit (Remote closed the connection) Jun 29 23:44:22 _pjp_, _pjp_, how come only gcc was showing errors and gcc -c is not showing errors?? Jun 29 23:44:33 ! Jun 29 23:44:36 * nandy_lost has quit (Read error: 110 (Connection timed out)) Jun 29 23:44:55 * suse_nj (n=root@59.178.169.121) has left #dgplug Jun 29 23:45:21 * atanubera (n=root@125.20.11.34) has left #dgplug Jun 29 23:45:24 may be _pjp_ is disconnected, wait a while Jun 29 23:45:37 kushal, ping Jun 29 23:46:05 * susenj_ (n=root@59.178.169.121) has joined #dgplug Jun 29 23:46:20 Soumya, seems all are disconnected Jun 29 23:46:35 may be kushal , _pjp_ all rae dc Jun 29 23:46:38 lets wait ria Jun 29 23:46:46 hmm Soumya :) Jun 29 23:46:58 Soumya, did your program give an output? Jun 29 23:47:01 may i know,how these nickname collision occuring frequently Jun 29 23:47:31 * susenj has quit (Read error: 110 (Connection timed out)) Jun 29 23:47:39 * susenj_ is now known as susenj Jun 29 23:47:42 Soumya, the sqrroot one? Jun 29 23:47:47 ria, i didn't get an output Jun 29 23:47:47 yes Jun 29 23:47:55 amrita, me too Jun 29 23:48:00 _pjp_, is dc may be Jun 29 23:48:14 yes Jun 29 23:48:16 wait Jun 29 23:48:21 amrita, ria , for that one read gcc --help Jun 29 23:48:32 Soumya, ya Jun 29 23:49:09 -c option only compiles and assembles but doesn't link to output file ria, amrita Jun 29 23:49:18 everyone wait for _pjp_ , he is in DNS problem Jun 29 23:49:19 Soumya, ya Jun 29 23:49:20 yes, correct Jun 29 23:49:30 * Subhodip wonders why people are logged is as root Jun 29 23:49:34 so nobody did receive the error Jun 29 23:49:35 Soumya, yes Jun 29 23:49:35 but how can get a obj file ? Jun 29 23:49:41 * i Jun 29 23:49:48 Soumya, i tried with gcc -o , but that will not work Jun 29 23:49:49 * Soumya supports Subhodip 's idea Jun 29 23:50:22 what do you mean by that t4num0y_cs3 Jun 29 23:50:24 Soumya, m=no error is showing on giving gcc -c but a.out file is not created Jun 29 23:50:40 you gave gcc -c (which creates a object file only ) so you got a object file Jun 29 23:50:46 cc hello.c gives you a obj file that is a.out ... Jun 29 23:50:47 arpita, yes, but hello.o Jun 29 23:50:48 see Jun 29 23:50:50 a.out file is the final output file Jun 29 23:50:59 yes arpita it will not create a.out Jun 29 23:51:01 but cc -c hello.c .. where is a.out ? Jun 29 23:51:08 t4num0y_cs3, no a.out Jun 29 23:51:12 it will create yourfilename.o file (means object file) Jun 29 23:51:13 that is what he is teaching Jun 29 23:51:14 kushal:yes hello.o only has created Jun 29 23:51:26 Soumya, so now to execute it what to do? Jun 29 23:51:34 let _pjp_ come Jun 29 23:51:37 wait Jun 29 23:51:42 he will tell you the details Jun 29 23:51:50 arpita, wait till here till _pjp_ comes Jun 29 23:52:00 arpita: ./ hello.out Jun 29 23:52:16 arpita, you can not Jun 29 23:52:20 coolpyro_rishi, FYI no out file is created Jun 29 23:52:27 arpita, that is what he is teaching Jun 29 23:52:32 bash: ./samp: cannot execute binary file Jun 29 23:52:38 hello.o is not executable code Jun 29 23:52:46 it is only object file Jun 29 23:52:48 samp is the obj file ..:) Jun 29 23:53:02 coolpyro_rishi, ./hello.out does not exist at all Jun 29 23:53:04 arpita: gcc -c hello.c -o hello.out Jun 29 23:53:12 try this Jun 29 23:53:13 kushal, you say me why gcc -c works but not gcc -o Jun 29 23:53:24 kushal, gcc -o gives errors Jun 29 23:53:28 ria, yes Jun 29 23:53:36 kushal, why? Jun 29 23:53:40 _pjp_, was telling in two steps Jun 29 23:53:46 first step is gcc -c Jun 29 23:53:51 please you people make it (no .out file is created) the last command created a object file .o (You cant execute .o file) Jun 29 23:54:04 kushal, ok Jun 29 23:54:30 _pjp_, is teaching to make it in two steps Jun 29 23:54:32 kushal, if i do gcc -c hello.c, how will i run the program Jun 29 23:54:34 ? Jun 29 23:54:37 * _pjp_1 (n=pjp@59.92.157.171) has joined #dgplug Jun 29 23:54:43 t4num0y_cs3, check if you have executable permission in your swamp file Jun 29 23:54:48 ria, wait Jun 29 23:54:51 _pjp_1, thank god you came Jun 29 23:54:59 <_pjp_1> sorry..that was some DNS problem. Jun 29 23:55:00 :) Jun 29 23:55:02 ria, learn to wait Jun 29 23:55:03 there was raining questions _pjp_1 Jun 29 23:55:08 Subhodip , ya chmod +x samp... Jun 29 23:55:13 Kishan, now hello.out is created but it is showing permission denied when i am trying to execute it Jun 29 23:55:18 but till same error .. :( Jun 29 23:55:30 kushal, now hello.out is created but it is showing permission denied when i am trying to execute it Jun 29 23:55:32 * pushkal (n=chatzill@117.197.18.9) has joined #dgplug Jun 29 23:55:35 ALL PLEASE FOLLOW ONLY _pjp_ _pjp_1 Jun 29 23:55:46 you people stop let _pjp_1 continue Jun 29 23:55:47 arpita, he never told you to do so Jun 29 23:55:52 pleaseeeeee Jun 29 23:55:56 <_pjp_1> why am I _pjp_1? Jun 29 23:56:04 ALL PLEASE STOP Jun 29 23:56:10 _pjp_, is ghost Jun 29 23:56:17 _pjp_1 /msg nickserv ghost _pjp_ yourpassword Jun 29 23:56:23 to ghost it Jun 29 23:56:29 yup Jun 29 23:56:29 <_pjp_1> okay..where were we? Jun 29 23:56:30 :) Jun 29 23:56:41 we were creating the object file .o Jun 29 23:56:43 gcc -c hello,c Jun 29 23:56:43 * _pjp_1 (n=pjp@59.92.157.171) has left #dgplug Jun 29 23:56:49 * indradg is now known as indradg|dinner Jun 29 23:56:58 * _pjp_1 (n=pjp@59.92.157.171) has joined #dgplug Jun 29 23:57:19 <_pjp_1> hello Jun 29 23:57:24 typo kushal Jun 29 23:57:30 gcc -c hello.c Jun 29 23:58:17 <_pjp_1> hello.and..sorry again. Jun 29 23:58:23 <_pjp_1> so where were we? Jun 29 23:58:26 gcc -c hello.c Jun 29 23:58:49 _pjp_:we get the file name as hello.o after -c option Jun 29 23:59:38 <_pjp_1> okay..so -c comes handy when you only want to get rid of the compilation errors without actually going through linking and code generation. Jun 29 23:59:53 * debayan has quit (Read error: 110 (Connection timed out)) Jun 30 00:00:38 after that what _pjp_1 how can we execute from .o file Jun 30 00:00:46 _pjp_:last two process is still left Jun 30 00:00:47 <_pjp_1> that'll anyway won't happen in case of compilation errors..but you can build static/dynamic libraries this way using -c. Jun 30 00:00:53 * _pjp_ has quit (Read error: 110 (Connection timed out)) Jun 30 00:00:56 deepak, Soumya, please STOP Jun 30 00:01:00 * Subhodip has quit ("Leaving") Jun 30 00:01:06 * nandy_lost_ has quit ("ChatZilla 0.9.83 [Firefox 3.0/2008052906]") Jun 30 00:01:31 * kushal gives channel operator status to Soumya Jun 30 00:01:35 <_pjp_1> Do all know about the static/dynamic libraries? Jun 30 00:01:41 no Jun 30 00:02:14 deepak:only heard Jun 30 00:02:17 <_pjp_1> anyways..first let's complete this..then will see about libraries. Jun 30 00:02:42 * samar has quit ("Ex-Chat") Jun 30 00:03:03 <_pjp_1> so now, to link the hello.o with the standard maths library say: $ gcc hello.o -lm Jun 30 00:03:10 <_pjp_1> or cc hello.o -lm Jun 30 00:03:33 i m sorry to disturb... but please.. someone paste the conversation on www.pastebin.com Jun 30 00:04:15 pushkal, only after the class Jun 30 00:04:22 kushal: ok Jun 30 00:04:26 <_pjp_1> the option -lm tells the compiler(ie. gcc) to link the executable file with the given library, in this case maths library. Jun 30 00:06:08 done Jun 30 00:06:23 <_pjp_1> because of this linking, when you execute the program, like say: ./a.out or ./hello the OS knows which libraries to load and from where. Jun 30 00:06:25 done Jun 30 00:06:40 ! Jun 30 00:07:06 <_pjp_1> ria: later please, 10 mins. Jun 30 00:07:13 ok Jun 30 00:07:22 Jun 30 00:07:29 <_pjp_1> so do you see the a.out or hello file again? Jun 30 00:07:44 <_pjp_1> delete the previous one, and try again. Jun 30 00:07:49 yes Jun 30 00:07:55 yup Jun 30 00:08:13 <_pjp_1> Great..execute that file. Jun 30 00:08:47 sqrroot of 9 , it gives 0 Jun 30 00:08:55 mine too Jun 30 00:09:03 <_pjp_1> he..he..could some one guess why? Jun 30 00:09:17 pushkal, http://pastebin.com/m2360d687 Jun 30 00:09:51 roni, talk in pm please Jun 30 00:10:03 ok Jun 30 00:10:09 sqroot of 9 is showing 0 Jun 30 00:10:21 arpita, yes, and _pjp_1 asked why ? Jun 30 00:10:21 ^^^^^^ Jun 30 00:10:51 sqrt takes float/double as an argumebt Jun 30 00:10:57 *argument Jun 30 00:11:16 * Debashree has quit (Read error: 104 (Connection reset by peer)) Jun 30 00:11:30 sqrt takes only double... Jun 30 00:11:33 something related to string _pjp_1 Jun 30 00:11:56 <_pjp_1> right..sqrt() returns a *double* value which can not be displayed using %d Jun 30 00:12:29 s/takes/returns Jun 30 00:13:06 <_pjp_1> kushal: ? Jun 30 00:13:22 * indradg|dinner is now known as indradg Jun 30 00:13:35 _pjp_1, not for you, the students said takes, I replaced it with returns Jun 30 00:13:42 _pjp_1, sorry to interrupt Jun 30 00:13:47 * Debashree (n=Debashre@61.2.165.135) has joined #dgplug Jun 30 00:13:55 <_pjp_1> Please replace %d with %f Jun 30 00:14:16 * mavu (n=satya@59.178.160.205) has joined #dgplug Jun 30 00:14:17 <_pjp_1> and compile->run again Jun 30 00:14:54 * mavu is now known as mavu_ Jun 30 00:15:02 <_pjp_1> does it works now? Jun 30 00:15:10 ! Jun 30 00:15:18 <_pjp_1> t4num0y_cs3: yes Jun 30 00:15:20 <_pjp_1> ? Jun 30 00:15:22 no Jun 30 00:15:31 no Jun 30 00:15:36 ./samp1.o: Permission denied Jun 30 00:15:42 no Jun 30 00:15:43 all students please link it also Jun 30 00:15:55 after cc -c samp1.c -lm Jun 30 00:15:59 <_pjp_1> what is the error? Jun 30 00:16:18 t4num0y_cs3, in two different lines Jun 30 00:16:19 _pjp_1 : Permission denied Jun 30 00:16:27 t4num0y_cs3, two commands Jun 30 00:16:28 <_pjp_1> t4num0y_cs3: no, -c does not do linking. Jun 30 00:16:29 not showing error, but the same output Jun 30 00:16:36 done Jun 30 00:16:54 yes still showing 0 as output Jun 30 00:16:54 same output Jun 30 00:16:55 <_pjp_1> ria: remove the old file and try again Jun 30 00:17:07 _pjp_1, i did so Jun 30 00:17:14 <_pjp_1> that's strange. Jun 30 00:17:22 <_pjp_1> wait a sec..I'll paste it. Jun 30 00:17:29 ria, please type the steps here Jun 30 00:17:56 _pjp_1, please change the nick and identify , I need to pm Jun 30 00:18:22 <_pjp_1> kushal: how do I change nicname? Jun 30 00:18:34 _pjp_1, /nick _pjp_ Jun 30 00:18:50 _pjp_1, then /msg nickserv identify yourpassword Jun 30 00:19:21 _pjp_1, is it wrong http://rafb.net/p/qMdEuV98.html ? Jun 30 00:19:25 <_pjp_1> http://rafb.net/p/HznzXg70.html Jun 30 00:19:50 kushal, if i change variable n's type from int to float correct output is showing...is that o.k??? Jun 30 00:19:56 <_pjp_1> ria: you need not change the data type of n. Jun 30 00:20:09 earlier i did so but did not work so i changed _pjp_1 Jun 30 00:20:32 ya me too changed data type and then it is working Jun 30 00:20:39 <_pjp_1> it's not wrong..but not necessary cause 9 is an integer. Jun 30 00:20:53 * indradg has quit (Remote closed the connection) Jun 30 00:20:58 ria, and main rever returns float Jun 30 00:21:04 s/rever/never Jun 30 00:21:47 _pjp_1, still the same Jun 30 00:21:53 _pjp_:again it is showing output as 0 Jun 30 00:22:16 _pjp_1, http://rafb.net/p/yHqWux73.html Jun 30 00:22:16 ria, please type your steps here Jun 30 00:22:40 ria, please type your steps here from the writing of the code by vim Jun 30 00:22:46 ! Jun 30 00:22:47 [ria@rialappy c]$ rm a.out Jun 30 00:23:08 [ria@rialappy c]$ gcc hello.o -lm Jun 30 00:23:26 [ria@rialappy c]$ ./a.out Jun 30 00:23:29 ria, first create that hello.o as your code changed Jun 30 00:23:33 <_pjp_1> ria: use hello.c Jun 30 00:23:37 ./gcc -c hello.c Jun 30 00:23:47 I mean $gcc -c hello.c Jun 30 00:23:49 <_pjp_1> you changed the source, not hello.o right? Jun 30 00:23:49 ok Jun 30 00:24:38 working Jun 30 00:24:43 ! Jun 30 00:24:44 kushal, ria my program is running correctly now Jun 30 00:25:01 kushal, without changing data type of n Jun 30 00:25:31 * chacha_chaudhry_ (n=rpmbuild@122.162.66.111) has joined #dgplug Jun 30 00:25:32 <_pjp_1> folks please note that, you can pass integer to a function which accepts float/double values, but the reverse is not allowed. Jun 30 00:25:55 ! Jun 30 00:26:28 <_pjp_1> that's why sqrt() can accept an integer, but it's return value can not be used with %d in printf(). Jun 30 00:27:51 ! Jun 30 00:27:51 _pjp_1, this implies square root function may accept an integer or floating value as arguement but will return a float type value always? Jun 30 00:28:22 <_pjp_1> correct. Jun 30 00:28:34 <_pjp_1> t4num0y_cs3: Jun 30 00:28:36 <_pjp_1> ? Jun 30 00:28:53 ya i got permission denied error everytime .. Jun 30 00:29:07 <_pjp_1> t4num0y_cs3: what are you doing? Jun 30 00:29:28 #cc -c samp1.c Jun 30 00:29:42 #cc samp1.c -lm Jun 30 00:29:49 <_pjp_1> t4num0y_cs3: Do not work as root user. Jun 30 00:30:15 t4num0y_cs3, cc sanple1.o -lm Jun 30 00:30:22 <_pjp_1> t4num0y_cs3: switch to some other user. Jun 30 00:30:55 ok ... Jun 30 00:31:07 * t4num0y_cs3 has quit ("Leaving") Jun 30 00:31:32 good boy Jun 30 00:31:37 _pjp_1, carry on please :) Jun 30 00:31:44 <_pjp_1> okay.. Jun 30 00:32:55 <_pjp_1> there are other useful options of gcc like `-x' to specify source file type, as gcc can also compile c++ sources. Jun 30 00:33:22 give one example _pjp_1 Jun 30 00:33:25 * t4num0y_cs3 (n=T4num0y@117.194.2.152) has joined #dgplug Jun 30 00:33:53 <_pjp_1> say: gcc -x c hello.c Jun 30 00:34:16 <_pjp_1> or copy hello.c to hello.txt and say: gcc -x c hello.txt Jun 30 00:34:30 <_pjp_1> you should get the same a.out file. Jun 30 00:35:03 <_pjp_1> this comes handy when a project includes both, C and C++ source files. Jun 30 00:35:23 * chacha_chaudhry has quit (Read error: 110 (Connection timed out)) Jun 30 00:35:43 <_pjp_1> other one is -std to specify the language standard. Jun 30 00:36:11 gcc -x c hjello.c is not working Jun 30 00:36:16 <_pjp_1> C language has more than one published standard so far. Jun 30 00:36:35 <_pjp_1> arpita: what happens? Jun 30 00:37:13 <_pjp_1> standard C89 is the most widely used and supported standard todate. Jun 30 00:37:35 ! Jun 30 00:37:47 ! Jun 30 00:38:32 _pjp_1 ,In function `main':hello.c:: undefined reference to `sqrt returned 1 exit status is the error showing Jun 30 00:38:46 <_pjp_1> All C compilers comply with the C89 standard. Jun 30 00:39:02 <_pjp_1> arpita: you did not link with -lm Jun 30 00:39:14 <_pjp_1> deepak: t4num0y_cs3: ? Jun 30 00:39:49 [deepak@localhost ~]$ cp hello1.c hello1.txt Jun 30 00:40:04 i used this as first Jun 30 00:40:10 same permission denied error .. Jun 30 00:40:19 my file name is hello1.c Jun 30 00:40:20 <_pjp_1> there is also C99 standard, but not all compilers support this, and thus still not portable enough. Jun 30 00:40:53 <_pjp_1> t4num0y_cs3: what did you do? Jun 30 00:40:53 [deepak@localhost ~]$ gcc -x c hello1.txt Jun 30 00:41:50 deepak, link it with -lm Jun 30 00:42:16 kushal:now it is ok Jun 30 00:42:21 $ cc -c hello.c Jun 30 00:42:23 $ cc -lm hello.c Jun 30 00:42:36 _pjp_1, can we directly do gcc -x hello.txt Jun 30 00:42:39 also $ cc -lm hello.o Jun 30 00:42:41 to get a.out ?? Jun 30 00:43:07 no i got hello.o Jun 30 00:43:10 <_pjp_1> Soumya: no, -x option asks for source language, and hello.txt is a file-name. Jun 30 00:44:23 ok so let any program be in hello.txt we should do gcc -x c hello.txt Jun 30 00:44:35 right _pjp_1 ? Jun 30 00:44:57 ! Jun 30 00:45:17 <_pjp_1> Soumya: not always -x c Jun 30 00:45:20 <_pjp_1> ria: ? Jun 30 00:45:39 then _pjp_1 ? Jun 30 00:45:43 _pjp_1 , ? Jun 30 00:45:46 if it combines 2 languages then will it be like gcc -x c c++ ? Jun 30 00:46:12 is the c for the c language? Jun 30 00:46:16 Jun 30 00:46:20 <_pjp_1> Soumya: I mean, specify the language of the program that is in hello.txt Jun 30 00:46:45 <_pjp_1> ria: c++ compiler understands C code, so you can just say -x c++ Jun 30 00:47:20 ok Jun 30 00:47:24 ok Jun 30 00:47:30 * chacha_chaudhry_ is now known as chacha_chaudhry Jun 30 00:47:39 _pjp_1, when there are 2 languages then? Jun 30 00:47:49 other than c and c++? Jun 30 00:48:02 can we use gcc +x? Jun 30 00:48:14 <_pjp_1> ria: gcc +x? Jun 30 00:48:26 sorry gcc -x Jun 30 00:48:56 <_pjp_1> folks there are other useful options like -I -L and -D etc. May be we'll talk about them tomorrow. Jun 30 00:49:11 <_pjp_1> for now let's take the questions. Jun 30 00:49:15 <_pjp_1> kushal: okay? Jun 30 00:49:39 <_pjp_1> ria: two languages in one file? Jun 30 00:50:09 no you were talking of combining 2 languages that's why _pjp_1 Jun 30 00:50:15 _pjp_1, perfect Jun 30 00:50:27 ! Jun 30 00:50:31 ya its not possible to have to languages in a file Jun 30 00:50:44 <_pjp_1> okay guys..let's hit the questions. :) Jun 30 00:50:46 <_pjp_1> t4num0y_cs3: ? Jun 30 00:50:59 ! Jun 30 00:51:02 <_pjp_1> Soumya: ? Jun 30 00:51:04 What about this Permission ? what i have to do ? Jun 30 00:51:21 <_pjp_1> t4num0y_cs3: I'm sorry, but I don't know what you are doing? Jun 30 00:51:43 _pjp_1, what you told in gcc -x c hello.txt was we should specify the language !! Jun 30 00:52:02 can you specify by some example and all so that i can get completely Jun 30 00:52:13 i have got you , but i need one example Jun 30 00:52:26 t4num0y_cs3, please type the steps in rafb and give us the link Jun 30 00:52:34 Soumya, like Jun 30 00:52:43 there is a file called kus.txt Jun 30 00:52:58 if inside it C code is there Jun 30 00:53:01 then Jun 30 00:53:10 gcc -x c kus.txt Jun 30 00:53:14 if C++ Jun 30 00:53:19 gcc -x c++ kus.txt Jun 30 00:53:25 <_pjp_1> Soumya: the program in hello.txt is written in C, so you say -x c Jun 30 00:53:37 anyone , any other question ? Jun 30 00:53:48 ! Jun 30 00:53:53 ria, yes Jun 30 00:54:03 why do we need to use it gcc -x? Jun 30 00:54:05 <_pjp_1> otherwise you could say -x c++ or -x ada or -x assembler etc. Jun 30 00:54:10 when is it needed Jun 30 00:54:17 ? Jun 30 00:54:24 Jun 30 00:54:32 <_pjp_1> ria: it's not always necessary, but sometimes useful. Jun 30 00:54:34 ! Jun 30 00:54:34 ria, like in a project you wrote files in C and C++ also (different files) Jun 30 00:54:50 ria, so then compiling each you can specify which language Jun 30 00:54:53 arpita, yes Jun 30 00:55:02 kushal, are there 2 files one with c and other c++? Jun 30 00:55:13 <_pjp_1> Soumya: ? Jun 30 00:55:28 ria, yes, (example ) Jun 30 00:55:38 ok kushal Jun 30 00:55:41 got it _pjp_1 , thank you Jun 30 00:55:50 t4num0y_cs3, there ? Jun 30 00:55:51 Kishan, gcc -x c hello.c is not working Jun 30 00:56:02 everything clear :) Jun 30 00:56:02 arpita, no, see the error Jun 30 00:56:03 * amrita_ (n=amrita@117.201.96.85) has joined #dgplug Jun 30 00:56:22 http://rafb.net/p/abIepp48.html Jun 30 00:56:22 arpita, and try to remember how you solved that error couple of minutes bac k Jun 30 00:56:30 * amrita has quit (Nick collision from services.) Jun 30 00:56:35 who is a ? Jun 30 00:56:39 * amrita_ is now known as amrita Jun 30 00:56:56