execable.c: forgot to do "svn add" again...

libbb/execable.c

@@ -0,0 +1,62 @@
+/* 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 tarball for details.
+ */
+
+#include "libbb.h"
+
+/* check if path points to an executable file;
+ * return 1 if found;
+ * return 0 otherwise;
+ */
+int execable_file(const char *name)
+{
+	struct stat s;
+	return (!access(name, X_OK) && !stat(name, &s) && S_ISREG(s.st_mode));
+}
+
+/* search $PATH for an executable file;
+ * return allocated string containing full path if found;
+ * return NULL otherwise;
+ */
+char *find_execable(const char *filename)
+{
+	char *path, *p, *n;
+
+	p = path = xstrdup(getenv("PATH") ? : "");
+	while (p) {
+		n = strchr(p, ':');
+		if (n)
+			*n++ = '\0';
+		if (*p != '\0') { /* it's not a PATH="foo::bar" situation */
+			p = concat_path_file(p, filename);
+			if (execable_file(p)) {
+				free(path);
+				return p;
+			}
+			free(p);
+		}
+		p = n;
+	}
+	free(path);
+	return NULL;
+}
+
+/* search $PATH for an executable file;
+ * return 1 if found;
+ * return 0 otherwise;
+ */
+int exists_execable(const char *filename)
+{
+	char *ret = find_execable(filename);
+	if (ret) {
+		free(ret);
+		return 1;
+	}
+	return 0;
+}
+