[SOLVED] Problem with pthread.h, compiling with gcc

[bleedingsamurai]

Ok so I was messing around trying to learn about threads and how to use them and now I'm trying to compile but I get an error like this:

fatal error: pthread: No such file or directory

however I have included the pthread.h header in my source file and the arguments I'm passing to gcc goes as follows:

gcc thread.c  -o thread -lpthread

and when I do a

whereis pthread.h

I get /usr/include/pthread.h so it seems to be here. I'm rather confused.

[drl]

Hi.

Perhaps this sample will help:

#!/usr/bin/env bash

# @(#) s1	Demonstrate compilation of pthreads code.

# Utility functions: print-as-echo, print-line-with-visual-space.
pe() { for i;do printf "%s" "$i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }

FILE=${1-pt.c}
pl " Sample of $FILE (local command specimen):"
pe
specimen $FILE

pl " Results of compiling $( wc -l < $FILE ) lines of file $FILE:"
gcc -lpthread $FILE
ls -lgG a.out

exit 0

producing:

% ./s1

-----
 Sample of pt.c (local command specimen):

Edges: 5:0:5 of 36 lines in file "pt.c"
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

void *print_message_function( void *ptr );
   ---
{
     char *message;
     message = (char *) ptr;
     printf("%s \n", message);
}

-----
 Results of compiling 36 lines of file pt.c:
-rwxr-xr-x 1 9617 Mar 11 05:20 a.out

Code from Linux Tutorial: POSIX Threads q.v.

Best wishes ... cheers, drl

[Rubberman]

Ok so I was messing around trying to learn about threads and how to use them and now I'm trying to compile but I get an error like this:

fatal error: pthread: No such file or directory

however I have included the pthread.h header in my source file and the arguments I'm passing to gcc goes as follows:

gcc thread.c  -o thread -lpthread

and when I do a

whereis pthread.h

I get /usr/include/pthread.h so it seems to be here. I'm rather confused.

On Linux, you need to use -pthread in the compile flags. It will know what libraries to link. IE:

gcc -pthread thread.c -o thread