This is procexec/t_system.c (Listing 27-7, page 581), an example from the book, The Linux Programming Interface.

The source code file is copyright 2022, Michael Kerrisk, and is licensed under the GNU General Public License, version 3.

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In the listing below, the names of Linux system calls and C library functions are hyperlinked to manual pages from the Linux man-pages project, and the names of functions implemented in the book are hyperlinked to the implementations of those functions.


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Function list (Bold in this list means a function is not static)

/* t_system.c

   Demonstrate the use of system(3) to execute a shell command.
#include <sys/wait.h>
#include "print_wait_status.h"
#include "tlpi_hdr.h"

#define MAX_CMD_LEN 200
main(int argc, char *argv[])
    char str[MAX_CMD_LEN];      /* Command to be executed by system() */
    int status;                 /* Status return from system() */

    for (;;) {                  /* Read and execute a shell command */
        printf("Command: ");
        if (fgets(str, MAX_CMD_LEN, stdin) == NULL)
            break;              /* end-of-file */

        status = system(str);
        printf("system() returned: status=0x%04x (%d,%d)\n",
                (unsigned int) status, status >> 8, status & 0xff);

        if (status == -1) {
        } else {
            if (WIFEXITED(status) && WEXITSTATUS(status) == 127)
                printf("(Probably) could not invoke shell\n");
            else                /* Shell successfully executed command */
                printWaitStatus(NULL, status);



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