4.4BSD/usr/src/usr.bin/more/main.c
/*
* Copyright (c) 1988 Mark Nudleman
* Copyright (c) 1988, 1993
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 Mark Nudleman.\n\
@(#) Copyright (c) 1988, 1993
Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)main.c 8.1 (Berkeley) 6/7/93";
#endif /* not lint */
/*
* Entry point, initialization, miscellaneous routines.
*/
#include <sys/types.h>
#include <sys/file.h>
#include <stdio.h>
#include <less.h>
int ispipe;
int new_file;
int is_tty;
char *current_file, *previous_file, *current_name, *next_name;
off_t prev_pos;
int any_display;
int scroll;
int ac;
char **av;
int curr_ac;
int quitting;
extern int file;
extern int cbufs;
extern int errmsgs;
extern char *tagfile;
extern int tagoption;
/*
* Edit a new file.
* Filename "-" means standard input.
* No filename means the "current" file, from the command line.
*/
edit(filename)
register char *filename;
{
extern int errno;
register int f;
register char *m;
off_t initial_pos, position();
static int didpipe;
char message[100], *p;
char *rindex(), *strerror(), *save(), *bad_file();
initial_pos = NULL_POSITION;
if (filename == NULL || *filename == '\0') {
if (curr_ac >= ac) {
error("No current file");
return(0);
}
filename = save(av[curr_ac]);
}
else if (strcmp(filename, "#") == 0) {
if (*previous_file == '\0') {
error("no previous file");
return(0);
}
filename = save(previous_file);
initial_pos = prev_pos;
} else
filename = save(filename);
/* use standard input. */
if (!strcmp(filename, "-")) {
if (didpipe) {
error("Can view standard input only once");
return(0);
}
f = 0;
}
else if ((m = bad_file(filename, message, sizeof(message))) != NULL) {
error(m);
free(filename);
return(0);
}
else if ((f = open(filename, O_RDONLY, 0)) < 0) {
(void)sprintf(message, "%s: %s", filename, strerror(errno));
error(message);
free(filename);
return(0);
}
if (isatty(f)) {
/*
* Not really necessary to call this an error,
* but if the control terminal (for commands)
* and the input file (for data) are the same,
* we get weird results at best.
*/
error("Can't take input from a terminal");
if (f > 0)
(void)close(f);
(void)free(filename);
return(0);
}
/*
* We are now committed to using the new file.
* Close the current input file and set up to use the new one.
*/
if (file > 0)
(void)close(file);
new_file = 1;
if (previous_file != NULL)
free(previous_file);
previous_file = current_file;
current_file = filename;
pos_clear();
prev_pos = position(TOP);
ispipe = (f == 0);
if (ispipe) {
didpipe = 1;
current_name = "stdin";
} else
current_name = (p = rindex(filename, '/')) ? p + 1 : filename;
if (curr_ac >= ac)
next_name = NULL;
else
next_name = av[curr_ac + 1];
file = f;
ch_init(cbufs, 0);
init_mark();
if (is_tty) {
int no_display = !any_display;
any_display = 1;
if (no_display && errmsgs > 0) {
/*
* We displayed some messages on error output
* (file descriptor 2; see error() function).
* Before erasing the screen contents,
* display the file name and wait for a keystroke.
*/
error(filename);
}
/*
* Indicate there is nothing displayed yet.
*/
if (initial_pos != NULL_POSITION)
jump_loc(initial_pos);
clr_linenum();
}
return(1);
}
/*
* Edit the next file in the command line list.
*/
next_file(n)
int n;
{
extern int quit_at_eof;
off_t position();
if (curr_ac + n >= ac) {
if (quit_at_eof || position(TOP) == NULL_POSITION)
quit();
error("No (N-th) next file");
}
else
(void)edit(av[curr_ac += n]);
}
/*
* Edit the previous file in the command line list.
*/
prev_file(n)
int n;
{
if (curr_ac - n < 0)
error("No (N-th) previous file");
else
(void)edit(av[curr_ac -= n]);
}
/*
* copy a file directly to standard output; used if stdout is not a tty.
* the only processing is to squeeze multiple blank input lines.
*/
static
cat_file()
{
extern int squeeze;
register int c, empty;
if (squeeze) {
empty = 0;
while ((c = ch_forw_get()) != EOI)
if (c != '\n') {
putchr(c);
empty = 0;
}
else if (empty < 2) {
putchr(c);
++empty;
}
}
else while ((c = ch_forw_get()) != EOI)
putchr(c);
flush();
}
main(argc, argv)
int argc;
char **argv;
{
int envargc, argcnt;
char *envargv[2], *getenv();
/*
* Process command line arguments and MORE environment arguments.
* Command line arguments override environment arguments.
*/
if (envargv[1] = getenv("MORE")) {
envargc = 2;
envargv[0] = "more";
envargv[2] = NULL;
(void)option(envargc, envargv);
}
argcnt = option(argc, argv);
argv += argcnt;
argc -= argcnt;
/*
* Set up list of files to be examined.
*/
ac = argc;
av = argv;
curr_ac = 0;
/*
* Set up terminal, etc.
*/
is_tty = isatty(1);
if (!is_tty) {
/*
* Output is not a tty.
* Just copy the input file(s) to output.
*/
if (ac < 1) {
(void)edit("-");
cat_file();
} else {
do {
(void)edit((char *)NULL);
if (file >= 0)
cat_file();
} while (++curr_ac < ac);
}
exit(0);
}
raw_mode(1);
get_term();
open_getchr();
init();
init_signals(1);
/* select the first file to examine. */
if (tagoption) {
/*
* A -t option was given; edit the file selected by the
* "tags" search, and search for the proper line in the file.
*/
if (!tagfile || !edit(tagfile) || tagsearch())
quit();
}
else if (ac < 1)
(void)edit("-"); /* Standard input */
else {
/*
* Try all the files named as command arguments.
* We are simply looking for one which can be
* opened without error.
*/
do {
(void)edit((char *)NULL);
} while (file < 0 && ++curr_ac < ac);
}
if (file >= 0)
commands();
quit();
/*NOTREACHED*/
}
/*
* Copy a string to a "safe" place
* (that is, to a buffer allocated by malloc).
*/
char *
save(s)
char *s;
{
char *p, *strcpy(), *malloc();
p = malloc((u_int)strlen(s)+1);
if (p == NULL)
{
error("cannot allocate memory");
quit();
}
return(strcpy(p, s));
}
/*
* Exit the program.
*/
quit()
{
/*
* Put cursor at bottom left corner, clear the line,
* reset the terminal modes, and exit.
*/
quitting = 1;
lower_left();
clear_eol();
deinit();
flush();
raw_mode(0);
exit(0);
}