/contrib/tcsh/tw.help.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 209 lines · 126 code · 24 blank · 59 comment · 41 complexity · caa59bc1a17deffc68241e5f39ec5a3a MD5 · raw file
- /* $Header: /p/tcsh/cvsroot/tcsh/tw.help.c,v 3.27 2006/08/24 20:56:31 christos Exp $ */
- /* tw.help.c: actually look up and print documentation on a file.
- * Look down the path for an appropriate file, then print it.
- * Note that the printing is NOT PAGED. This is because the
- * function is NOT meant to look at manual pages, it only does so
- * if there is no .help file to look in.
- */
- /*-
- * Copyright (c) 1980, 1991 The Regents of the University of California.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
- #include "sh.h"
- RCSID("$tcsh: tw.help.c,v 3.27 2006/08/24 20:56:31 christos Exp $")
- #include "tw.h"
- #include "tc.h"
- static int f = -1;
- static void cleanf (int);
- static Char *skipslist (Char *);
- static void nextslist (const Char *, Char *);
- static const char *const h_ext[] = {
- ".help", ".1", ".8", ".6", "", NULL
- };
- void
- do_help(const Char *command)
- {
- Char *name, *cmd_p;
- /* trim off the whitespace at the beginning */
- while (*command == ' ' || *command == '\t')
- command++;
- /* copy the string to a safe place */
- name = Strsave(command);
- cleanup_push(name, xfree);
- /* trim off the whitespace that may be at the end */
- for (cmd_p = name;
- *cmd_p != ' ' && *cmd_p != '\t' && *cmd_p != '\0'; cmd_p++)
- continue;
- *cmd_p = '\0';
- /* if nothing left, return */
- if (*name == '\0') {
- cleanup_until(name);
- return;
- }
- if (adrof1(STRhelpcommand, &aliases)) { /* if we have an alias */
- jmp_buf_t osetexit;
- size_t omark;
- getexit(osetexit); /* make sure to come back here */
- omark = cleanup_push_mark();
- if (setexit() == 0)
- aliasrun(2, STRhelpcommand, name); /* then use it. */
- cleanup_pop_mark(omark);
- resexit(osetexit); /* and finish up */
- }
- else { /* else cat something to them */
- Char *thpath, *hpath; /* The environment parameter */
- Char *curdir; /* Current directory being looked at */
- struct Strbuf full = Strbuf_INIT;
- /* got is, now "cat" the file based on the path $HPATH */
- hpath = str2short(getenv(SEARCHLIST));
- if (hpath == NULL)
- hpath = str2short(DEFAULTLIST);
- thpath = hpath = Strsave(hpath);
- cleanup_push(thpath, xfree);
- curdir = xmalloc((Strlen(thpath) + 1) * sizeof (*curdir));
- cleanup_push(curdir, xfree);
- cleanup_push(&full, Strbuf_cleanup);
- for (;;) {
- const char *const *sp;
- size_t ep;
- if (!*hpath) {
- xprintf(CGETS(29, 1, "No help file for %S\n"), name);
- break;
- }
- nextslist(hpath, curdir);
- hpath = skipslist(hpath);
- /*
- * now make the full path name - try first /bar/foo.help, then
- * /bar/foo.1, /bar/foo.8, then finally /bar/foo.6. This is so
- * that you don't spit a binary at the tty when $HPATH == $PATH.
- */
- full.len = 0;
- Strbuf_append(&full, curdir);
- Strbuf_append(&full, STRslash);
- Strbuf_append(&full, name);
- ep = full.len;
- for (sp = h_ext; *sp; sp++) {
- full.len = ep;
- Strbuf_append(&full, str2short(*sp));
- Strbuf_terminate(&full);
- if ((f = xopen(short2str(full.s), O_RDONLY|O_LARGEFILE)) != -1)
- break;
- }
- if (f != -1) {
- unsigned char buf[512];
- sigset_t oset, set;
- struct sigaction osa, sa;
- ssize_t len;
- /* so cat it to the terminal */
- cleanup_push(&f, open_cleanup);
- sa.sa_handler = cleanf;
- sigemptyset(&sa.sa_mask);
- sa.sa_flags = 0;
- (void)sigaction(SIGINT, &sa, &osa);
- cleanup_push(&osa, sigint_cleanup);
- (void)sigprocmask(SIG_UNBLOCK, &set, &oset);
- cleanup_push(&oset, sigprocmask_cleanup);
- while ((len = xread(f, buf, sizeof(buf))) > 0)
- (void) xwrite(SHOUT, buf, len);
- cleanup_until(&f);
- #ifdef convex
- /* print error in case file is migrated */
- if (len == -1)
- stderror(ERR_SYSTEM, progname, strerror(errno));
- #endif /* convex */
- break;
- }
- }
- }
- cleanup_until(name);
- }
- static void
- /*ARGSUSED*/
- cleanf(int snum)
- {
- USE(snum);
- if (f != -1)
- xclose(f);
- f = -1;
- }
- /* these next two are stolen from CMU's man(1) command for looking down
- * paths. they are prety straight forward. */
- /*
- * nextslist takes a search list and copies the next path in it
- * to np. A null search list entry is expanded to ".".
- * If there are no entries in the search list, then np will point
- * to a null string.
- */
- static void
- nextslist(const Char *sl, Char *np)
- {
- if (!*sl)
- *np = '\000';
- else if (*sl == ':') {
- *np++ = '.';
- *np = '\000';
- }
- else {
- while (*sl && *sl != ':')
- *np++ = *sl++;
- *np = '\000';
- }
- }
- /*
- * skipslist returns the pointer to the next entry in the search list.
- */
- static Char *
- skipslist(Char *sl)
- {
- while (*sl && *sl++ != ':')
- continue;
- return (sl);
- }