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-rw-r--r--lib/shell.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/lib/shell.c b/lib/shell.c
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+++ b/lib/shell.c
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+/*
+ * SPDX-FileCopyrightText: 1989 - 1991, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2003 - 2006, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2009 , Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <stdio.h>
+#include <errno.h>
+#include "prototypes.h"
+#include "defines.h"
+#include "string/sprintf.h"
+
+
+extern char **newenvp;
+extern size_t newenvc;
+
+/*
+ * shell - execute the named program
+ *
+ * shell begins by trying to figure out what argv[0] is going to
+ * be for the named process. The user may pass in that argument,
+ * or it will be the last pathname component of the file with a
+ * '-' prepended.
+ * Then, it executes the named file.
+ */
+
+int shell (const char *file, /*@null@*/const char *arg, char *const envp[])
+{
+ int err;
+ char arg0[1024];
+
+ if (file == NULL) {
+ errno = EINVAL;
+ return errno;
+ }
+
+ /*
+ * The argv[0]'th entry is usually the path name, but
+ * for various reasons the invoker may want to override
+ * that. So, we determine the 0'th entry only if they
+ * don't want to tell us what it is themselves.
+ */
+ if (arg == NULL) {
+ SNPRINTF(arg0, "-%s", Basename(file));
+ arg = arg0;
+ }
+
+ /*
+ * First we try the direct approach. The system should be
+ * able to figure out what we are up to without too much
+ * grief.
+ */
+ (void) execle (file, arg, (char *) NULL, envp);
+ err = errno;
+
+ if (access (file, R_OK|X_OK) == 0) {
+ /*
+ * Assume this is a shell script (with no shebang).
+ * Interpret it with /bin/sh
+ */
+ (void) execle (SHELL, "sh", "-", file, (char *) NULL, envp);
+ err = errno;
+ }
+
+ /*
+ * Obviously something is really wrong - I can't figure out
+ * how to execute this stupid shell, so I might as well give
+ * up in disgust ...
+ */
+ SNPRINTF(arg0, _("Cannot execute %s"), file);
+ errno = err;
+ perror (arg0);
+ return err;
+}
+