how to run system command in c

how to run system command in c

• Use system( ) to run the command if input and output are not important.
• Use popen( ) if control on either input or output is needed.

System:

• system() is used to invoke an operating system command from a C/C++ program.
• int system(const char *command);
• stdlib.h  is needed

• Using system(), we can execute any command that can run on terminal if operating system allows. 
• For example, we can call system(“dir”) on Windows and system(“ls”) to list contents of a directory.

Example Program:

#include <stdio.h>

#include <string.h>

int main () {

    char command[256];

    strcpy( command, "ls -l" );

    system(command);

   

    return 0;

}

Output:

sample$ ./a.out

total 156

-rw-rw-r-- 1 labuser labuser     159 Dec 18 21:59 '

-rw-rw-r-- 1 labuser labuser     338 Aug  3  2017 ]

-rw-rw-r-- 1 labuser labuser    1035 May 16  2017 access.c

-rwxrwxr-x 1 labuser labuser    8688 Apr 23 21:52 a.out

-rw-rw-r-- 1 labuser labuser     231 May 16  2017 array_init.c

-rw-rw-r-- 1 labuser labuser     585 May 19  2017 array_size.c

-rw-rw-r-- 1 labuser labuser     347 Aug 30  2017 assert.c

-rw-rw-r-- 1 labuser labuser     992 Jan 31 21:14 backtrace.c