Add "help" command. (Building help/help.h requires python, but I'll ship

that file with release versions.)

3 files changed, 92 insertions, 2 deletions

diff --git a/toys/Config.in b/toys/Config.in
index 2e9127dc..e6f9636c 100644
--- a/toys/Config.in
+++ b/toys/Config.in
@@ -1,5 +1,16 @@
 menu "Toys"
 
+# Fake config symbol to attach help entry to.
+
+config TOYBOX
+	bool
+	default n
+	help
+	  usage: toybox [command] [arguments...]
+
+	  With no arguments, shows available commands.  First argument is
+	  name of a command to run, followed by any arguments to that command.
+
 config BZCAT
 	bool "bzcat"
 	default n
@@ -90,6 +101,22 @@ config HELLO
 	help
 	  A hello world program.  You don't need this.
 
+config HELP
+	bool "help"
+	default y
+	help
+	  usage: help [command]
+
+	  Show usage information for toybox commands.
+
+config HELP_LONG
+	bool "Verbose help text"
+	default y
+	depends on HELP
+	help
+	  Show more than one line of help information per command.
+
+
 config MDEV
 	bool "mdev"
 	default n
@@ -216,7 +243,7 @@ config READLINK_F
 	help
 	  usage: readlink [-f]
 
-	  -f         Show final location, including normal files and multiple symlinks.
+	  -f	Show final location, including normal files and multiple symlinks.
 
 config SLEEP
 	bool "sleep"
@@ -366,6 +393,35 @@ config TOYSH_BUILTINS
 	  Adds the commands exec, fg, bg, help, jobs, pwd, export, source, set,
 	  unset, read, alias.
 
+config EXIT
+	bool
+	default n
+	depends on TOYSH
+	help
+	  usage: exit [status]
+
+	  Exit shell.  If no return value supplied on command line, use value
+	  of most recent command, or 0 if none.
+
+config CD
+	bool
+	default n
+	depends on TOYSH
+	help
+	  usage: cd [path]
+
+	  Change current directory.  With no arguments, go to $HOME.
+
+config CD_P
+	bool # "-P support for cd"
+	default n
+	depends on TOYSH
+	help
+	  usage: cd [-PL]
+
+	  -P	Physical path: resolve symlinks in path.
+	  -L	Cancel previous -P and restore default behavior.
+
 config TRUE
 	bool "true"
 	default y
diff --git a/toys/help.c b/toys/help.c
new file mode 100644
index 00000000..6af743fc
--- /dev/null
+++ b/toys/help.c
@@ -0,0 +1,33 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * help.c - Show help for toybox
+ */
+
+#include "toys.h"
+#include "toys/help.h"
+
+#undef NEWTOY
+#undef OLDTOY
+#define NEWTOY(name,opt,flags) help_##name "\0"
+#define OLDTOY(name,oldname,opts,flags) "\xff" #oldname "\0"
+static char *help_data =
+#include "toys/toylist.h"
+;
+
+int help_main(void)
+{
+	struct toy_list *t = toy_find(*toys.optargs);
+	int i = t-toy_list;
+	char *s = help_data;
+
+	if (!t) error_exit("Unknown command '%s'\n", *toys.optargs);
+	for (;;) {
+		while (i--) s += strlen(s) + 1;
+		if (*s != 255) break;
+		i = toy_find(++s)-toy_list;
+		s = help_data;
+	}
+
+	printf("%s", s);
+	return 0;
+}
diff --git a/toys/toylist.h b/toys/toylist.h
index 0b3845d9..deeb6204 100644
--- a/toys/toylist.h
+++ b/toys/toylist.h
@@ -95,7 +95,8 @@ USE_DF(NEWTOY(df, "Pkt*a", TOYFLAG_USR|TOYFLAG_SBIN))
 USE_ECHO(NEWTOY(echo, "+en", TOYFLAG_BIN))
 USE_TOYSH(NEWTOY(exit, NULL, TOYFLAG_NOFORK))
 USE_FALSE(NEWTOY(false, NULL, TOYFLAG_BIN))
-USE_HELLO(NEWTOY(hello, NULL, TOYFLAG_USR))
+USE_HELLO(NEWTOY(hello, NULL, TOYFLAG_USR|TOYFLAG_BIN))
+USE_HELP(NEWTOY(help, "<1", TOYFLAG_BIN))
 USE_MKE2FS(NEWTOY(mke2fs, MKE2FS_OPTSTRING, TOYFLAG_SBIN))
 USE_ONEIT(NEWTOY(oneit, "+<1p", TOYFLAG_SBIN))
 USE_PWD(NEWTOY(pwd, NULL, TOYFLAG_BIN))