Annotation of 42BSD/usr.lib/libU77/system_.c, revision 1.1

1.1     ! root        1: /*
        !             2: char id_system[] = "@(#)system_.c      1.5";
        !             3:  *
        !             4:  * execute a unix command
        !             5:  *
        !             6:  * calling sequence:
        !             7:  *     iexit = system(command)
        !             8:  * where:
        !             9:  *     iexit will return the exit status of the command
        !            10:  *     command is a character string containing the command to be executed
        !            11:  */
        !            12: 
        !            13: #include       "../libI77/fiodefs.h"
        !            14: #include       "../libI77/f_errno.h"
        !            15: #include <sys/param.h>
        !            16: #ifndef        NCARGS
        !            17: #define NCARGS 256
        !            18: #endif
        !            19: 
        !            20:  
        !            21: long system_(s, n)
        !            22: char *s;
        !            23: long n;
        !            24: {
        !            25:        char buf[NCARGS - 50];
        !            26:        long i;
        !            27: 
        !            28:        if (n >= sizeof buf)
        !            29:                return(-(long)(errno=F_ERARG));
        !            30:        for (i = 0; i < MXUNIT; i++)
        !            31:                flush_(&i);
        !            32:        g_char(s, n, buf);
        !            33:        return((long)system(buf));
        !            34: }
        !            35: 
        !            36: /*
        !            37:  * this is a sane version of the libc/stdio routine.
        !            38:  */
        !            39: 
        !            40: #include       <signal.h>
        !            41: 
        !            42: char   *getenv();
        !            43: char   *rindex();
        !            44: 
        !            45: system(s)
        !            46: char *s;
        !            47: {
        !            48:        register int (*istat)(), (*qstat)();
        !            49:        int status, pid, w;
        !            50:        char    *shname, *shell;
        !            51: 
        !            52:        if ((shell = getenv("SHELL")) == NULL)
        !            53:                shell = "/bin/sh";
        !            54: 
        !            55:        if (shname = rindex(shell, '/'))
        !            56:                shname++;
        !            57:        else
        !            58:                shname = shell;
        !            59: 
        !            60:        if ((pid = fork()) == 0) {
        !            61:                execl(shell, shname, "-c", s, 0);
        !            62:                _exit(127);
        !            63:        }
        !            64:        istat = signal(SIGINT, SIG_IGN);
        !            65:        qstat = signal(SIGQUIT, SIG_IGN);
        !            66:        while ((w = wait(&status)) != pid && w != -1)
        !            67:                ;
        !            68:        if (w == -1)
        !            69:                status = -1;
        !            70:        signal(SIGINT, istat);
        !            71:        signal(SIGQUIT, qstat);
        !            72:        return(status);
        !            73: }

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