4.3BSD - /usr/src/lib/libc/gen/execvp.c

   1: #if defined(LIBC_SCCS) && !defined(lint)
   2: static char sccsid[] = "@(#)execvp.c	5.2 (Berkeley) 3/9/86";
   3: #endif LIBC_SCCS and not lint
   4: 
   5: /*
   6:  *	execlp(name, arg,...,0)	(like execl, but does path search)
   7:  *	execvp(name, argv)	(like execv, but does path search)
   8:  */
   9: #include <errno.h>
  10: #define NULL    0
  11: 
  12: static  char shell[] =  "/bin/sh";
  13: char    *execat(), *getenv();
  14: extern  errno;
  15: 
  16: execlp(name, argv)
  17: char *name, *argv;
  18: {
  19:     return(execvp(name, &argv));
  20: }
  21: 
  22: execvp(name, argv)
  23: char *name, **argv;
  24: {
  25:     char *pathstr;
  26:     register char *cp;
  27:     char fname[128];
  28:     char *newargs[256];
  29:     int i;
  30:     register unsigned etxtbsy = 1;
  31:     register eacces = 0;
  32: 
  33:     if ((pathstr = getenv("PATH")) == NULL)
  34:         pathstr = ":/bin:/usr/bin";
  35:     cp = index(name, '/')? "": pathstr;
  36: 
  37:     do {
  38:         cp = execat(cp, name, fname);
  39:     retry:
  40:         execv(fname, argv);
  41:         switch(errno) {
  42:         case ENOEXEC:
  43:             newargs[0] = "sh";
  44:             newargs[1] = fname;
  45:             for (i=1; newargs[i+1]=argv[i]; i++) {
  46:                 if (i>=254) {
  47:                     errno = E2BIG;
  48:                     return(-1);
  49:                 }
  50:             }
  51:             execv(shell, newargs);
  52:             return(-1);
  53:         case ETXTBSY:
  54:             if (++etxtbsy > 5)
  55:                 return(-1);
  56:             sleep(etxtbsy);
  57:             goto retry;
  58:         case EACCES:
  59:             eacces++;
  60:             break;
  61:         case ENOMEM:
  62:         case E2BIG:
  63:             return(-1);
  64:         }
  65:     } while (cp);
  66:     if (eacces)
  67:         errno = EACCES;
  68:     return(-1);
  69: }
  70: 
  71: static char *
  72: execat(s1, s2, si)
  73: register char *s1, *s2;
  74: char *si;
  75: {
  76:     register char *s;
  77: 
  78:     s = si;
  79:     while (*s1 && *s1 != ':')
  80:         *s++ = *s1++;
  81:     if (si != s)
  82:         *s++ = '/';
  83:     while (*s2)
  84:         *s++ = *s2++;
  85:     *s = '\0';
  86:     return(*s1? ++s1: 0);
  87: }

Defined functions

Defined variables

Defined macros