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/* $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);
}
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