[project @ 1998-02-02 17:27:26 by simonm]

[ghc-hetmet.git] / ghc / lib / posix / cbits / execvpe.c

diff --git a/ghc/lib/posix/cbits/execvpe.c b/ghc/lib/posix/cbits/execvpe.c
new file mode 100644 (file)
index 0000000..ab50ccd
--- /dev/null
+++ b/ghc/lib/posix/cbits/execvpe.c
@@ -0,0 +1,153 @@
+/*
+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1995-1996
+%
+\subsection[posix.lc]{executeFile Runtime Support}
+
+\begin{code}
+*/
+#if !defined(_AIX)
+#define NON_POSIX_SOURCE
+#endif
+
+#include "rtsdefs.h"
+#include "libposix.h"
+
+/* 
+ * We want the search semantics of execvp, but we want to provide our
+ * own environment, like execve.  The following copyright applies to
+ * this code, as it is a derivative of execvp:
+ *-
+ * Copyright (c) 1991 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *     This product includes software developed by the University of
+ *     California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+int
+execvpe(char *name, char **argv, char **envp)
+{
+    register int lp, ln;
+    register char *p;
+    int eacces, etxtbsy;
+    char *bp, *cur, *path, *buf;
+
+    /* If it's an absolute or relative path name, it's easy. */
+    if (strchr(name, '/')) {
+       bp = (char *) name;
+       cur = path = buf = NULL;
+       goto retry;
+    }
+
+    /* Get the path we're searching. */
+    if (!(path = getenv("PATH"))) {
+#ifdef HAVE_CONFSTR
+        ln = confstr(_CS_PATH, NULL, 0);
+        if ((cur = path = malloc(ln + 1)) != NULL) {
+           path[0] = ':';
+           (void) confstr (_CS_PATH, path + 1, ln);
+       }
+#else
+        if ((cur = path = malloc(1 + 1)) != NULL) {
+           path[0] = ':';
+           path[1] = '\0';
+       }
+#endif
+    } else
+       cur = path = strDup(path);
+
+    if (path == NULL || (bp = buf = malloc(strlen(path)+strlen(name)+2)) == NULL)
+       goto done;
+
+    eacces = etxtbsy = 0;
+    while (cur != NULL) {
+       p = cur;
+        if ((cur = strchr(cur, ':')) != NULL)
+           *cur++ = '\0';
+
+       /*
+        * It's a SHELL path -- double, leading and trailing colons mean the current
+        * directory.
+        */
+       if (!*p) {
+           p = ".";
+           lp = 1;
+       } else
+           lp = strlen(p);
+       ln = strlen(name);
+
+       memcpy(buf, p, lp);
+       buf[lp] = '/';
+       memcpy(buf + lp + 1, name, ln);
+       buf[lp + ln + 1] = '\0';
+
+      retry:
+        (void) execve(bp, argv, envp);
+       switch (errno) {
+       case EACCES:
+           eacces = 1;
+           break;
+       case ENOENT:
+           break;
+       case ENOEXEC:
+           {
+               register size_t cnt;
+               register char **ap;
+
+               for (cnt = 0, ap = (char **) argv; *ap; ++ap, ++cnt)
+                   ;
+               if ((ap = malloc((cnt + 2) * sizeof(char *))) != NULL) {
+                   memcpy(ap + 2, argv + 1, cnt * sizeof(char *));
+
+                   ap[0] = "sh";
+                   ap[1] = bp;
+                   (void) execve("/bin/sh", ap, envp);
+                   free(ap);
+               }
+               goto done;
+           }
+       case ETXTBSY:
+           if (etxtbsy < 3)
+               (void) sleep(++etxtbsy);
+           goto retry;
+       default:
+           goto done;
+       }
+    }
+    if (eacces)
+       errno = EACCES;
+    else if (!errno)
+       errno = ENOENT;
+  done:
+    if (path)
+       free(path);
+    if (buf)
+       free(buf);
+    return (-1);
+}