Implement which. Add hello world to menuconfig. Wrap the various applet main

functions in main.c with USE() macros so --gc-sections can strip them.

7 files changed, 143 insertions, 67 deletions

diff --git a/lib/functions.c b/lib/functions.c
index 0b003fd6..bcdaa0e0 100644
--- a/lib/functions.c
+++ b/lib/functions.c
@@ -241,69 +241,45 @@ char *xabspath(char *path)
 	return path;
 }
 
-// Check whether a file exists, or is executable, or...
-int is_file_type(char *path, int type)
-{
-	// Is there a file here we can execute?
-	if (!access(path, type)) {
-		struct stat st;
-		// Confirm it's not a directory.
-		if (!stat(path, &st) && S_ISREG(st.st_mode)) return 1;
-	}
-
-	return 0;
-}
-
-
-// Find an exectuable file either at a path with a slash in it (absolute or
-// relative to current directory), or in $PATH.  Returns absolute path to file,
-// or NULL if not found.
-
+// Find all file in a colon-separated path with access type "type" (generally
+// X_OK or R_OK).  Returns a list of absolute paths to each file found, in
+// order.
 
-char *which_in_path(char *filename)
+struct string_list *find_in_path(char *path, char *filename)
 {
-	char *res;
-
-	if (index(filename, '/')) {
-		res = xabspath(filename);
-		if (is_file_type(filename, X_OK)) return res;
-		free(res);
-		return NULL;
-	}
-	return find_in_path(getenv("PATH"), filename, X_OK);
-}
-
-// Find file in a colon-separated path with access type "type" (generally
-// X_OK or R_OK).  Returns absolute path to file, or NULL if not found.
-
-char *find_in_path(char *path, char *filename, int type)
-{
-	char *res = NULL, *cwd = xgetcwd();
+	struct string_list *rlist = NULL;
+	char *cwd = xgetcwd();
 
 	for (;;) {
 		char *next = path ? index(path, ':') : NULL;
 		int len = next ? next-path : strlen(path);
+		struct string_list *rnext;
+		struct stat st;
 
-		if (!len) res = xmsprintf("%s/%s", cwd, filename);
+		rnext = xmalloc(sizeof(void *) + strlen(filename)
+			+ (len ? len : strlen(cwd)) + 2);
+		if (!len) sprintf(rnext->str, "%s/%s", cwd, filename);
 		else {
-			res = xmalloc(len+strlen(filename)+2);
+			char *res = rnext->str;
 			strncpy(res, path, len);
-			res[len] = '/';
-			strcpy(res+len+1, filename);
+			res += len;
+			*(res++) = '/';
+			strcpy(res, filename);
 		}
 
-		// Is there a file here we can execute?
-		if (is_file_type(res, type)) break;
+		// Confirm it's not a directory.
+		if (!stat(rnext->str, &st) && S_ISREG(st.st_mode)) {
+			rnext->next = rlist;
+			rlist = rnext;
+		} else free(rnext);
 
-		free(res);
-		res = NULL;
 		if (!next) break;
 		path += len;
 		path++;
 	}
 	free(cwd);
 
-	return res;
+	return rlist;
 
 }
 
diff --git a/lib/lib.h b/lib/lib.h
index 10d33bde..d013af9d 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -4,6 +4,15 @@
  * Copyright 2006 Rob Landley <rob@landley.net>
  */
 
+// llist.c
+void llist_free(void *list, void (*freeit)(void *data));
+void *llist_pop(void *list);  // actually void **list, but the compiler's dumb
+
+struct string_list {
+	struct string_list *next;
+	char str[0];
+};
+
 // functions.c
 void verror_msg(char *msg, int err, va_list va);
 void error_msg(char *msg, ...);
@@ -25,22 +34,12 @@ ssize_t readall(int fd, void *buf, size_t count);
 void xread(int fd, char *buf, size_t count);
 char *xgetcwd(void);
 char *xabspath(char *path);
-int is_file_type(char *path, int type);
-char *which_in_path(char *filename);
-char *find_in_path(char *path, char *filename, int type);
+struct string_list *find_in_path(char *path, char *filename);
 void utoa_to_buf(unsigned n, char *buf, unsigned buflen);
 void itoa_to_buf(int n, char *buf, unsigned buflen);
 char *utoa(unsigned n);
 char *itoa(int n);
 
-// llist.c
-void llist_free(void *list, void (*freeit)(void *data));
-
-struct string_list {
-	struct string_list *next;
-	char *str;
-};
-
 // getmountlist.c
 struct mtab_list {
 	struct mtab_list *next;
diff --git a/lib/llist.c b/lib/llist.c
index 9047e8b5..8d6fd265 100644
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -12,10 +12,21 @@
 void llist_free(void *list, void (*freeit)(void *data))
 {
 	while (list) {
-		void **next = (void **)list;
-		void *list_next = *next;
-		if (freeit) freeit(list);
-		free(list);
-		list = list_next;
+		void *pop = llist_pop(&list);
+		if (freeit) freeit(pop);
 	}
 }
+
+// Return the first item from the list, advancing the list (which must be called
+// as &list)
+void *llist_pop(void *list)
+{
+	// I'd use a void ** for the argument, and even accept the typecast in all
+	// callers as documentation you need the &, except the stupid compiler
+	// would then scream about type-punned pointers.  Screw it.
+	void **llist = (void **)list;
+	void **next = (void **)*llist;
+	*llist = *next;
+
+	return (void *)next;
+}
diff --git a/main.c b/main.c
index de349ec6..00d76312 100644
--- a/main.c
+++ b/main.c
@@ -14,12 +14,13 @@ struct toy_list toy_list[] = {
 	// This one is out of order on purpose.
 	{"toybox", toybox_main, 0},
 	// The rest of these are alphabetical, for binary search.
-	{"cd", cd_main, TOYFLAG_NOFORK},
-	{"df", df_main, TOYFLAG_USR|TOYFLAG_SBIN},
-	{"exit", exit_main, TOYFLAG_NOFORK},
-	{"hello", hello_main, TOYFLAG_NOFORK|TOYFLAG_USR},
-	{"sh", toysh_main, TOYFLAG_BIN},
-	{"toysh", toysh_main, TOYFLAG_BIN}
+	USE_TOYSH({"cd", cd_main, TOYFLAG_NOFORK},)
+	USE_DF({"df", df_main, TOYFLAG_USR|TOYFLAG_SBIN},)
+	USE_TOYSH({"exit", exit_main, TOYFLAG_NOFORK},)
+	USE_HELLO({"hello", hello_main, TOYFLAG_NOFORK|TOYFLAG_USR},)
+	USE_TOYSH({"sh", toysh_main, TOYFLAG_BIN},)
+	USE_TOYSH({"toysh", toysh_main, TOYFLAG_BIN},)
+	USE_WHICH({"which", which_main, TOYFLAG_USR|TOYFLAG_BIN},)
 };
 
 #define TOY_LIST_LEN (sizeof(toy_list)/sizeof(struct toy_list))
diff --git a/toys.h b/toys.h
index 810af89c..c07e565b 100644
--- a/toys.h
+++ b/toys.h
@@ -31,6 +31,7 @@ int exit_main(void);
 int hello_main(void);
 int toybox_main(void);
 int toysh_main(void);
+int which_main(void);
 
 #define TOYFLAG_USR      (1<<0)
 #define TOYFLAG_BIN      (1<<1)
diff --git a/toys/Config.in b/toys/Config.in
index d9b1da10..89481bde 100644
--- a/toys/Config.in
+++ b/toys/Config.in
@@ -28,6 +28,12 @@ config DF_PEDANTIC
 
 	  -k	Sets units back to 1024 bytes (the default without -P)
 
+config HELLO
+	bool "hello"
+	default n
+	help
+	  A hello world program.  You don't need this.
+
 config TOYSH
 	bool "sh (toysh)"
 	default n
@@ -146,5 +152,15 @@ config TOYSH_BUILTINS
 	  Adds the commands exec, fg, bg, help, jobs, pwd, export, source, set,
 	  unset, read, alias.
 
+config WHICH
+	bool "Which"
+	default n
+	help
+	  usage: which [-a] filename ...
+
+	  Search $PATH for executable files matching filename(s).
+
+	  -a	Show all matches
+
 endmenu
 
diff --git a/toys/which.c b/toys/which.c
new file mode 100644
index 00000000..6d00bc82
--- /dev/null
+++ b/toys/which.c
@@ -0,0 +1,72 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * which.c - 
+ *
+ * Copyright 2006 Rob landley <rob@landley.net>
+ */
+
+#include "toys.h"
+
+#define OPTIONS "a"
+#define OPT_a   1
+
+// Find an exectuable file either at a path with a slash in it (absolute or
+// relative to current directory), or in $PATH.  Returns absolute path to file,
+// or NULL if not found.
+
+static int which_in_path(char *filename)
+{
+	struct string_list *list;
+
+	// If they gave us a path, don't worry about $PATH or -a
+
+	if (index(filename, '/')) {
+		// Confirm it has the executable bit set, and it's not a directory.
+		if (!access(filename, X_OK)) {
+			struct stat st;
+
+			if (!stat(filename, &st) && S_ISREG(st.st_mode)) {
+				puts(filename);
+				return 0;
+			}
+			return 1;
+		}
+	}
+
+	// Search $PATH for matches.
+	list = find_in_path(getenv("PATH"), filename);
+	if (!list) return 1;
+
+	// Print out matches
+	while (list) {
+		if (!access(list->str, X_OK)) {
+			puts(list->str);
+			// If we should stop at one match, do so
+			if (toys.optflags & OPT_a) {
+				llist_free(list, NULL);
+				break;
+			}
+		}
+		free(llist_pop(&list));
+	}
+
+	return 0;
+}
+
+int which_main(void)
+{
+	char **argv;
+	int rc = 0;
+
+	// get_optflags(OPTIONS);
+	argv = toys.argv+1;
+
+	if (!*argv) rc++;
+	else {
+		int i;
+		for (i=0; argv[i]; i++)	rc |= which_in_path(argv[i]);
+	}
+	// if (CFG_TOYS_FREE) free(argv);
+
+	return rc;
+}