Merge branch 'busybox' into merge

Conflicts:
	debianutils/which.c
	editors/vi.c
	libbb/executable.c

1 files changed, 106 insertions, 0 deletions

diff --git a/libbb/executable.c b/libbb/executable.c
new file mode 100644
index 000000000..2e5f6a1b7
--- /dev/null
+++ b/libbb/executable.c
@@ -0,0 +1,106 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 2006 Gabriel Somlo <somlo at cmu.edu>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+#include "libbb.h"
+
+/* check if path points to an executable file;
+ * return 1 if found;
+ * return 0 otherwise;
+ */
+int FAST_FUNC file_is_executable(const char *name)
+{
+        struct stat s;
+        return (!access(name, X_OK) && !stat(name, &s) && S_ISREG(s.st_mode));
+}
+
+/* search (*PATHp) for an executable file;
+ * return allocated string containing full path if found;
+ *  PATHp points to the component after the one where it was found
+ *  (or NULL),
+ *  you may call find_executable again with this PATHp to continue
+ *  (if it's not NULL).
+ * return NULL otherwise; (PATHp is undefined)
+ * in all cases (*PATHp) contents will be trashed (s/:/NUL/).
+ */
+#if !ENABLE_PLATFORM_MINGW32
+#define next_path_sep(s) strchr(s, ':')
+#endif
+
+char* FAST_FUNC find_executable(const char *filename, char **PATHp)
+{
+        /* About empty components in $PATH:
+         * http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap08.html
+         * 8.3 Other Environment Variables - PATH
+         * A zero-length prefix is a legacy feature that indicates the current
+         * working directory. It appears as two adjacent colons ( "::" ), as an
+         * initial colon preceding the rest of the list, or as a trailing colon
+         * following the rest of the list.
+         */
+        char *p, *n;
+#if ENABLE_PLATFORM_MINGW32
+        char *w;
+#endif
+
+        p = *PATHp;
+        while (p) {
+                n = (char*)next_path_sep(p);
+                if (n)
+                        *n++ = '\0';
+                p = concat_path_file(
+                        p[0] ? p : ".", /* handle "::" case */
+                        filename
+                );
+                if (file_is_executable(p)) {
+                        *PATHp = n;
+                        return p;
+                }
+#if ENABLE_PLATFORM_MINGW32
+                else if ((w=win32_execable_file(p))) {
+                        *PATHp = n;
+                        free(p);
+                        return w;
+                }
+#endif
+                free(p);
+                p = n;
+        } /* on loop exit p == NULL */
+        return p;
+}
+
+/* search $PATH for an executable file;
+ * return 1 if found;
+ * return 0 otherwise;
+ */
+int FAST_FUNC executable_exists(const char *filename)
+{
+        char *path = xstrdup(getenv("PATH"));
+        char *tmp = path;
+        char *ret = find_executable(filename, &tmp);
+        free(path);
+        free(ret);
+        return ret != NULL;
+}
+
+#if ENABLE_FEATURE_PREFER_APPLETS
+/* just like the real execvp, but try to launch an applet named 'file' first */
+int FAST_FUNC BB_EXECVP(const char *file, char *const argv[])
+{
+        if (find_applet_by_name(file) >= 0)
+                execvp(bb_busybox_exec_path, argv);
+        return execvp(file, argv);
+}
+#endif
+
+int FAST_FUNC BB_EXECVP_or_die(char **argv)
+{
+        BB_EXECVP(argv[0], argv);
+        /* SUSv3-mandated exit codes */
+        xfunc_error_retval = (errno == ENOENT) ? 127 : 126;
+        bb_perror_msg_and_die("can't execute '%s'", argv[0]);
+}