mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-15 10:17:20 +00:00
92 lines
1.7 KiB
C
92 lines
1.7 KiB
C
/*
|
|
* Pager: Routines to create a "more" running out of a particular file
|
|
* descriptor.
|
|
*
|
|
* Copyright 1987, 1988 by MIT Student Information Processing Board
|
|
*
|
|
* For copyright information, see copyright.h.
|
|
*/
|
|
|
|
#include "ss_internal.h"
|
|
#include "copyright.h"
|
|
#include <stdio.h>
|
|
#include <sys/file.h>
|
|
#include <signal.h>
|
|
#include <unistd.h>
|
|
|
|
static char MORE[] = "more";
|
|
extern char *_ss_pager_name;
|
|
extern char *getenv();
|
|
extern int errno;
|
|
|
|
/*
|
|
* this needs a *lot* of work....
|
|
*
|
|
* run in same process
|
|
* handle SIGINT sensibly
|
|
* allow finer control -- put-page-break-here
|
|
*/
|
|
void ss_page_stdin();
|
|
|
|
#ifndef NO_FORK
|
|
int ss_pager_create()
|
|
{
|
|
int filedes[2];
|
|
|
|
if (pipe(filedes) != 0)
|
|
return(-1);
|
|
|
|
switch(fork()) {
|
|
case -1:
|
|
return(-1);
|
|
case 0:
|
|
/*
|
|
* Child; dup read half to 0, close all but 0, 1, and 2
|
|
*/
|
|
if (dup2(filedes[0], 0) == -1)
|
|
exit(1);
|
|
ss_page_stdin();
|
|
default:
|
|
/*
|
|
* Parent: close "read" side of pipe, return
|
|
* "write" side.
|
|
*/
|
|
(void) close(filedes[0]);
|
|
return(filedes[1]);
|
|
}
|
|
}
|
|
#else /* don't fork */
|
|
int ss_pager_create()
|
|
{
|
|
int fd;
|
|
fd = open("/dev/tty", O_WRONLY, 0);
|
|
return fd;
|
|
}
|
|
#endif
|
|
|
|
void ss_page_stdin()
|
|
{
|
|
int i;
|
|
for (i = 3; i < 32; i++)
|
|
(void) close(i);
|
|
(void) signal(SIGINT, SIG_DFL);
|
|
{
|
|
register int mask = sigblock(0);
|
|
mask &= ~sigmask(SIGINT);
|
|
sigsetmask(mask);
|
|
}
|
|
if (_ss_pager_name == (char *)NULL) {
|
|
if ((_ss_pager_name = getenv("PAGER")) == (char *)NULL)
|
|
_ss_pager_name = MORE;
|
|
}
|
|
(void) execlp(_ss_pager_name, _ss_pager_name, (char *) NULL);
|
|
{
|
|
/* minimal recovery if pager program isn't found */
|
|
char buf[80];
|
|
register int n;
|
|
while ((n = read(0, buf, 80)) > 0)
|
|
write(1, buf, n);
|
|
}
|
|
exit(errno);
|
|
}
|