usr/src/lib/libbc/libc/gen/common/execvp.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*LINTLIBRARY*/
  33 /*
  34  *      execlp(name, arg,...,0) (like execl, but does path search)
  35  *      execvp(name, argv)      (like execv, but does path search)
  36  */
  37 #include <errno.h>
  38 #include <sys/param.h>
  39 #include <stdarg.h>
  40 #include <string.h>
  41 #include <stdlib.h>
  42 #include <unistd.h>
  43
  44 static char *execat(char *, char *, char *);
  45 static char *shell = "/bin/sh";
  46
  47 int
  48 execlp(char *name, ...)
  49 {
  50         va_list args;
  51         int     r;
  52
  53         va_start(args, name);
  54         r = execvp(name, (char **)args);
  55         va_end(args);
  56
  57         return (r);
  58 }
  59
  60 int
  61 execvp(char *name, char **argv)
  62 {
  63         char    *pathstr;
  64         char    fname[MAXPATHLEN];
  65         char    *newargs[256];
  66         int     i;
  67         char    *cp;
  68         unsigned etxtbsy = 1;
  69         int     eacces = 0;
  70
  71         if ((pathstr = getenv("PATH")) == NULL)
  72                 pathstr = ":/usr/ucb:/bin:/usr/bin";
  73         cp = strchr(name, '/') ? "": pathstr;
  74
  75         do {
  76                 cp = execat(cp, name, fname);
  77         retry:
  78                 (void) execv(fname, argv);
  79                 switch (errno) {
  80                 case ENOEXEC:
  81                         newargs[0] = "sh";
  82                         newargs[1] = fname;
  83                         for (i = 1; (newargs[i+1] = argv[i]) != NULL; ++i) {
  84                                 if (i >= 254) {
  85                                         errno = E2BIG;
  86                                         return(-1);
  87                                 }
  88                         }
  89                         (void) execv(shell, newargs);
  90                         return (-1);
  91                 case ETXTBSY:
  92                         if (++etxtbsy > 5)
  93                                 return (-1);
  94                         (void) sleep(etxtbsy);
  95                         goto retry;
  96                 case EACCES:
  97                         ++eacces;
  98                         break;
  99                 case ENOMEM:
 100                 case E2BIG:
 101                 case EFAULT:
 102                         return (-1);
 103                 }
 104         } while (cp);
 105         if (eacces)
 106                 errno = EACCES;
 107         return (-1);
 108 }
 109
 110 static char *
 111 execat(char *s1, char *s2, char *si)
 112 {
 113         char    *s;
 114         char    *end;
 115
 116         s = si;
 117         end = s + MAXPATHLEN;
 118         while (*s1 && *s1 != ':' && s < end)
 119                 *s++ = *s1++;
 120         if (si != s && s < end)
 121                 *s++ = '/';
 122         while (*s2 && s < end)
 123                 *s++ = *s2++;
 124         *s = '\0';
 125         return (*s1 ? ++s1: 0);
 126 }