1 /* $Header: /p/tcsh/cvsroot/tcsh/tw.help.c,v 3.27 2006/08/24 20:56:31 christos Exp $ */
2 /* tw.help.c: actually look up and print documentation on a file.
3 * Look down the path for an appropriate file, then print it.
4 * Note that the printing is NOT PAGED. This is because the
5 * function is NOT meant to look at manual pages, it only does so
6 * if there is no .help file to look in.
9 * Copyright (c) 1980, 1991 The Regents of the University of California.
10 * All rights reserved.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 RCSID("$tcsh: tw.help.c,v 3.27 2006/08/24 20:56:31 christos Exp $")
45 static void cleanf (int);
46 static Char *skipslist (Char *);
47 static void nextslist (const Char *, Char *);
49 static const char *const h_ext[] = {
50 ".help", ".1", ".8", ".6", "", NULL
54 do_help(const Char *command)
58 /* trim off the whitespace at the beginning */
59 while (*command == ' ' || *command == '\t')
62 /* copy the string to a safe place */
63 name = Strsave(command);
64 cleanup_push(name, xfree);
66 /* trim off the whitespace that may be at the end */
68 *cmd_p != ' ' && *cmd_p != '\t' && *cmd_p != '\0'; cmd_p++)
72 /* if nothing left, return */
78 if (adrof1(STRhelpcommand, &aliases)) { /* if we have an alias */
82 getexit(osetexit); /* make sure to come back here */
83 omark = cleanup_push_mark();
85 aliasrun(2, STRhelpcommand, name); /* then use it. */
86 cleanup_pop_mark(omark);
87 resexit(osetexit); /* and finish up */
89 else { /* else cat something to them */
90 Char *thpath, *hpath; /* The environment parameter */
91 Char *curdir; /* Current directory being looked at */
92 struct Strbuf full = Strbuf_INIT;
94 /* got is, now "cat" the file based on the path $HPATH */
96 hpath = str2short(getenv(SEARCHLIST));
98 hpath = str2short(DEFAULTLIST);
99 thpath = hpath = Strsave(hpath);
100 cleanup_push(thpath, xfree);
101 curdir = xmalloc((Strlen(thpath) + 1) * sizeof (*curdir));
102 cleanup_push(curdir, xfree);
103 cleanup_push(&full, Strbuf_cleanup);
106 const char *const *sp;
110 xprintf(CGETS(29, 1, "No help file for %S\n"), name);
113 nextslist(hpath, curdir);
114 hpath = skipslist(hpath);
117 * now make the full path name - try first /bar/foo.help, then
118 * /bar/foo.1, /bar/foo.8, then finally /bar/foo.6. This is so
119 * that you don't spit a binary at the tty when $HPATH == $PATH.
122 Strbuf_append(&full, curdir);
123 Strbuf_append(&full, STRslash);
124 Strbuf_append(&full, name);
126 for (sp = h_ext; *sp; sp++) {
128 Strbuf_append(&full, str2short(*sp));
129 Strbuf_terminate(&full);
130 if ((f = xopen(short2str(full.s), O_RDONLY|O_LARGEFILE)) != -1)
134 unsigned char buf[512];
136 struct sigaction osa, sa;
139 /* so cat it to the terminal */
140 cleanup_push(&f, open_cleanup);
141 sa.sa_handler = cleanf;
142 sigemptyset(&sa.sa_mask);
144 (void)sigaction(SIGINT, &sa, &osa);
145 cleanup_push(&osa, sigint_cleanup);
146 (void)sigprocmask(SIG_UNBLOCK, &set, &oset);
147 cleanup_push(&oset, sigprocmask_cleanup);
148 while ((len = xread(f, buf, sizeof(buf))) > 0)
149 (void) xwrite(SHOUT, buf, len);
152 /* print error in case file is migrated */
154 stderror(ERR_SYSTEM, progname, strerror(errno));
173 /* these next two are stolen from CMU's man(1) command for looking down
174 * paths. they are prety straight forward. */
177 * nextslist takes a search list and copies the next path in it
178 * to np. A null search list entry is expanded to ".".
179 * If there are no entries in the search list, then np will point
184 nextslist(const Char *sl, Char *np)
188 else if (*sl == ':') {
193 while (*sl && *sl != ':')
200 * skipslist returns the pointer to the next entry in the search list.
206 while (*sl && *sl++ != ':')