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/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $Id$
*/
/*
* Simple paged-output and paged-viewing functions
*/
#include "stand.h"
#include <string.h>
static int p_maxlines = -1;
static int p_freelines;
static char *pager_prompt1 = " --more-- <space> page down <enter> line down <q> quit ";
static char *pager_blank = " ";
/*
* 'open' the pager
*/
void
pager_open(void)
{
int nlines;
char *cp, *lp;
nlines = 24; /* sensible default */
if ((cp = getenv("LINES")) != NULL) {
nlines = strtol(cp, &lp, 0);
}
p_maxlines = nlines - 1;
if (p_maxlines < 1)
p_maxlines = 1;
p_freelines = p_maxlines;
}
/*
* 'close' the pager
*/
void
pager_close(void)
{
p_maxlines = -1;
}
/*
* Emit lines to the pager; may not return until the user
* has responded to the prompt.
*
* Will return nonzero if the user enters 'q' or 'Q' at the prompt.
*
* XXX note that this watches outgoing newlines (and eats them), but
* does not handle wrap detection (req. count of columns).
*/
int
pager_output(const char *cp)
{
int action;
if (cp == NULL)
return(0);
for (;;) {
if (*cp == 0)
return(0);
putchar(*cp); /* always emit character */
if (*(cp++) == '\n') { /* got a newline? */
p_freelines--;
if (p_freelines <= 0) {
printf(pager_prompt1);
action = 0;
while (action == 0) {
switch(getchar()) {
case '\r':
case '\n':
p_freelines = 1;
action = 1;
break;
case ' ':
p_freelines = p_maxlines;
action = 1;
break;
case 'q':
case 'Q':
action = 2;
break;
default:
break;
}
}
printf("\r%s\r", pager_blank);
if (action == 2)
return(1);
}
}
}
}
/*
* Display from (fd).
*/
int
pager_file(char *fname)
{
char buf[80];
size_t hmuch;
int fd;
int result;
if ((fd = open(fname, O_RDONLY)) == -1) {
printf("can't open '%s': %s\n", fname, strerror(errno));
return(-1);
}
pager_open();
for (;;) {
hmuch = read(fd, buf, sizeof(buf) - 1);
if (hmuch == -1) {
result = -1;
break;
}
if (hmuch == 0) {
result = 0;
break;
}
buf[hmuch] = 0;
if (pager_output(buf)) {
result = 1;
break;
}
}
pager_close();
close(fd);
return(result);
}
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