NetBSD-5.0.2/distrib/utils/more/os.c
/* $NetBSD: os.c,v 1.7 2003/10/13 14:34:25 agc Exp $ */
/*
* Copyright (c) 1988 Mark Nudelman
* Copyright (c) 1988, 1993
* 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 <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)os.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: os.c,v 1.7 2003/10/13 14:34:25 agc Exp $");
#endif
#endif /* not lint */
/*
* Operating system dependent routines.
*
* Most of the stuff in here is based on Unix, but an attempt
* has been made to make things work on other operating systems.
* This will sometimes result in a loss of functionality, unless
* someone rewrites code specifically for the new operating system.
*
* The makefile provides defines to decide whether various
* Unix features are present.
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <signal.h>
#include <setjmp.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include "less.h"
#include "extern.h"
#include "pathnames.h"
int reading;
static jmp_buf read_label;
/*
* Pass the specified command to a shell to be executed.
* Like plain "system()", but handles resetting terminal modes, etc.
*/
void
lsystem(cmd)
char *cmd;
{
int inp;
char cmdbuf[256];
char *shell;
/*
* Print the command which is to be executed,
* unless the command starts with a "-".
*/
if (cmd[0] == '-')
cmd++;
else
{
lower_left();
clear_eol();
putstr("!");
putstr(cmd);
putstr("\n");
}
/*
* De-initialize the terminal and take out of raw mode.
*/
deinit();
flush();
raw_mode(0);
/*
* Restore signals to their defaults.
*/
init_signals(0);
/*
* Force standard input to be the terminal, "/dev/tty",
* even if less's standard input is coming from a pipe.
*/
inp = dup(0);
(void)close(0);
if (open(_PATH_TTY, O_RDONLY, 0) < 0)
(void)dup(inp);
/*
* Pass the command to the system to be executed.
* If we have a SHELL environment variable, use
* <$SHELL -c "command"> instead of just <command>.
* If the command is empty, just invoke a shell.
*/
if ((shell = getenv("SHELL")) != NULL && *shell != '\0')
{
if (*cmd == '\0')
cmd = shell;
else
{
(void)snprintf(cmdbuf, sizeof(cmdbuf), "%s -c \"%s\"",
shell, cmd);
cmd = cmdbuf;
}
}
if (*cmd == '\0')
cmd = "sh";
(void)system(cmd);
/*
* Restore standard input, reset signals, raw mode, etc.
*/
(void)close(0);
(void)dup(inp);
(void)close(inp);
init_signals(1);
raw_mode(1);
init();
screen_trashed = 1;
#if defined(SIGWINCH) || defined(SIGWIND)
/*
* Since we were ignoring window change signals while we executed
* the system command, we must assume the window changed.
*/
winch(SIGWINCH);
#endif
}
/*
* Like read() system call, but is deliberately interruptable.
* A call to intread() from a signal handler will interrupt
* any pending iread().
*/
int
iread(fd, buf, len)
int fd;
char *buf;
int len;
{
int n;
if (setjmp(read_label))
/*
* We jumped here from intread.
*/
return (READ_INTR);
flush();
reading = 1;
n = read(fd, buf, len);
reading = 0;
if (n < 0)
return (-1);
return (n);
}
void
intread()
{
(void)sigsetmask(0L);
longjmp(read_label, 1);
}
/*
* Expand a filename, substituting any environment variables, etc.
* The implementation of this is necessarily very operating system
* dependent. This implementation is unabashedly only for Unix systems.
*/
char *
glob(filename)
char *filename;
{
FILE *f;
char *p;
int ch;
char *cmd;
static char buffer[MAXPATHLEN];
size_t l;
if (filename[0] == '#')
return (filename);
/*
* We get the shell to expand the filename for us by passing
* an "echo" command to the shell and reading its output.
*/
p = getenv("SHELL");
if (p == NULL || *p == '\0')
{
/*
* Read the output of <echo filename>.
*/
asprintf(&cmd, "echo \"%s\"", filename);
if (cmd == NULL)
return (filename);
} else
{
/*
* Read the output of <$SHELL -c "echo filename">.
*/
asprintf(&cmd, "%s -c \"echo %s\"", p, filename);
if (cmd == NULL)
return (filename);
}
if ((f = popen(cmd, "r")) == NULL)
return (filename);
free(cmd);
for (p = buffer; p < &buffer[sizeof(buffer)-1]; p++)
{
if ((ch = getc(f)) == '\n' || ch == EOF)
break;
*p = ch;
}
*p = '\0';
(void)pclose(f);
return(buffer);
}
char *
bad_file(filename, message, len)
char *filename, *message;
u_int len;
{
struct stat statbuf;
if (stat(filename, &statbuf) < 0) {
(void)snprintf(message, len, "%s: %s", filename,
strerror(errno));
return(message);
}
if ((statbuf.st_mode & S_IFMT) == S_IFDIR) {
static char is_dir[] = " is a directory";
strtcpy(message, filename, (int)(len-sizeof(is_dir)-1));
(void)strlcat(message, is_dir, len);
return(message);
}
return((char *)NULL);
}
/*
* Copy a string, truncating to the specified length if necessary.
* Unlike strncpy(), the resulting string is guaranteed to be null-terminated.
*/
void
strtcpy(to, from, len)
char *to, *from;
int len;
{
(void)strncpy(to, from, (int)len);
to[len-1] = '\0';
}