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Thanks all for bottom-posting! But why isn't anyone snipping out the same, repeating, unnecessary text? On 04/16/08 10:10, H.S. wrote: > John Salmon wrote: >> Sven Joachim <[EMAIL PROTECTED]> wrote in >> news:[EMAIL PROTECTED]: >> >>> On 2008-04-15 20:39 +0200, John Salmon wrote: >>> >>>> I'm running Debian Etch on a PC. When I try to compile the following >>>> (called test.c); >>>> >>>> #include <math.h> >>>> #include <stdio.h> >>>> >>>> int main() >>>> { >>>> double >>>> val = 1.55; >>>> >>>> printf("sine: %g\n", sin(val)); >>>> >>>> return 0; >>>> } >>>> >>>> using the command line >>>> >>>> gcc -Wall -o test test.c >>>> >>>> I get >>>> >>>> /tmp/cciDV02m.o: In function `main': >>>> test.c:(.text+0x21): undefined reference to `sin' >>>> collect2: ld returned 1 exit status >>> You need to link to the math library by specifying -lm _at the end_ of >>> the gcc command line, otherwise the linker does not know about the sin() >>> function. >>> >>>> When I compile the equivalent C++ program using the apropriate C++ >>>> parameters, everything goes great. Have I neglected to load a Debian >>>> package? Any help will be appreciated. >>> That is to be expected, because C++ programs are automatically linked >>> against the math library. In C you have to tell the linker to use it >>> with -lm. >>> >>> Sven >>> >>> >> >> That solved the linking problem. Now, after a successful compilation, >> when I run 'test' I gen no output. ??? >> > > In the directory where you source and output executable is, try "./test". > > You are not getting any output probably because you are inadvertently > using the system "test" command. > > To avoid such introduction traps, I usually make such example programs > with names quite different from any commands that the system may have, > for example by using my initials or by using a number in the source > file. Using "mytest" or "example1" would have been a better choice in > your case. - -- Ron Johnson, Jr. Jefferson LA USA We want... a Shrubbery!! -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFIBlXmS9HxQb37XmcRAjZHAKDMzYLjX3JH68Qm4UOdLIWop2UmkQCeJusw 0PDbdYFU1Qqs9vL2VOxI/z8= =5DqE -----END PGP SIGNATURE----- -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
