From a2cd46a5f342553c05ae6ef4e7a73069df0e1be1 Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Fri, 3 Jan 2020 03:10:17 -0600
Subject: Add MAYFORK to "help", teach it to behave differently when called as
 a builtin, and add -u.

---
 lib/help.c        | 11 ++++++++---
 lib/lib.c         |  2 +-
 lib/lib.h         |  3 ++-
 main.c            |  2 +-
 toys/other/help.c | 35 +++++++++++++++++++++++------------
 5 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/lib/help.c b/lib/help.c
index 7b97e8b9..86d6392b 100644
--- a/lib/help.c
+++ b/lib/help.c
@@ -16,10 +16,10 @@ static char *help_data =
 #include "generated/newtoys.h"
 ;
 
-void show_help(FILE *out)
+void show_help(FILE *out, int full)
 {
   int i = toys.which-toy_list;
-  char *s;
+  char *s, *ss;
 
   if (CFG_TOYBOX_HELP) {
     for (;;) {
@@ -30,6 +30,11 @@ void show_help(FILE *out)
       i = toy_find(++s)-toy_list;
     }
 
-    fprintf(out, "%s\n", s);
+    if (full) fprintf(out, "%s\n", s);
+    else {
+      strstart(&s, "usage: ");
+      for (ss = s; *ss && *ss!='\n'; ss++);
+      fprintf(out, "%.*s\n", (int)(ss-s), s);
+    }
   }
 }
diff --git a/lib/lib.c b/lib/lib.c
index 2250caf4..26ba546f 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -72,7 +72,7 @@ void help_exit(char *msg, ...)
 {
   va_list va;
 
-  if (!msg) show_help(stdout);
+  if (!msg) show_help(stdout, 1);
   else {
     va_start(va, msg);
     verror_msg(msg, -1, va);
diff --git a/lib/lib.h b/lib/lib.h
index 5ec648c8..398d261d 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -55,6 +55,7 @@ struct num_cache *add_num_cache(struct num_cache **cache, long long num,
 
 // args.c
 #define FLAGS_NODASH (1LL<<63)
+#define FLAGS_BUILTIN (1LL<<62)
 void get_optflags(void);
 
 // dirtree.c
@@ -107,7 +108,7 @@ struct dirtree *dirtree_read(char *path, int (*callback)(struct dirtree *node));
 
 // help.c
 
-void show_help(FILE *out);
+void show_help(FILE *out, int full);
 
 // Tell xopen and friends to print warnings but return -1 as necessary
 // The largest O_BLAH flag so far is arch/alpha's O_PATH at 0x800000 so
diff --git a/main.c b/main.c
index 9d892e69..fc1461f6 100644
--- a/main.c
+++ b/main.c
@@ -89,7 +89,7 @@ static void toy_singleinit(struct toy_list *which, char *argv[])
     if (!strcmp(argv[1], "--help")) {
       if (CFG_TOYBOX && toys.which == toy_list && toys.argv[2])
         if (!(toys.which = toy_find(toys.argv[2]))) unknown(toys.argv[2]);
-      show_help(stdout);
+      show_help(stdout, 1);
       xexit();
     }
 
diff --git a/toys/other/help.c b/toys/other/help.c
index 6ce1b02e..eba3cb1e 100644
--- a/toys/other/help.c
+++ b/toys/other/help.c
@@ -4,7 +4,7 @@
  *
  * Often a shell builtin.
 
-USE_HELP(NEWTOY(help, ""USE_HELP_EXTRAS("ah"), TOYFLAG_BIN))
+USE_HELP(NEWTOY(help, ""USE_HELP_EXTRAS("ahu"), TOYFLAG_BIN|TOYFLAG_MAYFORK))
 
 config HELP
   bool "help"
@@ -22,9 +22,10 @@ config HELP_EXTRAS
   depends on TOYBOX
   depends on HELP
   help
-    usage: help [-ah]
+    usage: help [-ah] [COMMAND]
 
     -a	All commands
+    -u	Usage only
     -h	HTML output
 */
 
@@ -33,13 +34,13 @@ config HELP_EXTRAS
 
 static void do_help(struct toy_list *t)
 {
-  if (toys.optflags & FLAG_h) 
+  if (FLAG(h))
     xprintf("<a name=\"%s\"><h1>%s</h1><blockquote><pre>\n", t->name, t->name);
 
   toys.which = t;
-  show_help(stdout);
+  show_help(stdout, !FLAG(u));
 
-  if (toys.optflags & FLAG_h) xprintf("</blockquote></pre>\n");
+  if (FLAG(h)) xprintf("</blockquote></pre>\n");
 }
 
 // The simple help is just toys.which = toy_find("name"); show_help(stdout);
@@ -48,8 +49,18 @@ static void do_help(struct toy_list *t)
 void help_main(void)
 {
   int i;
-  
-  if (!(toys.optflags & FLAG_a)) {
+
+  // If called with no arguments as a builtin form the shell, show all builtins
+  if (!*toys.optargs && (toys.optflags&FLAGS_BUILTIN)) {
+    for (i = 0; i < toys.toycount; i++) {
+      if (!(toy_list[i].flags&(TOYFLAG_NOFORK|TOYFLAG_MAYFORK))) continue;
+      toys.which = toy_list+i;
+      show_help(stdout, 0);
+    }
+    return;
+  }
+
+  if (!FLAG(a)) {
     struct toy_list *t = toys.which;
 
     if (*toys.optargs && !(t = toy_find(*toys.optargs)))
@@ -58,7 +69,7 @@ void help_main(void)
     return;
   }
 
-  if (toys.optflags & FLAG_h) {
+  if (FLAG(h)) {
     xprintf("<html>\n<title>Toybox command list</title>\n<body>\n<p>\n");
     for (i=0; i < toys.toycount; i++)
       xprintf("<a href=\"#%s\">%s\n</a>\n", toy_list[i].name,
@@ -67,15 +78,15 @@ void help_main(void)
   }
 
   for (i = 0; i < toys.toycount; i++) {
-    if (toys.optflags & FLAG_h) xprintf("<hr>\n<pre>\n");
-    else {
+    if (FLAG(h)) xprintf("<hr>\n<pre>\n");
+    else if (!FLAG(u)) {
       memset(toybuf, '-', 78);
       memcpy(toybuf+3, toy_list[i].name, strlen(toy_list[i].name));
       printf("\n%s\n\n", toybuf);
     }
     do_help(toy_list+i);
-    if (toys.optflags & FLAG_h) xprintf("</pre>\n");
+    if (FLAG(h)) xprintf("</pre>\n");
   }
 
-  if (toys.optflags & FLAG_h) xprintf("</html>");
+  if (FLAG(h)) xprintf("</html>");
 }
-- 
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