358 lines
6.2 KiB
C
358 lines
6.2 KiB
C
/*
|
|
* Copyright (C) 1984-2015 Mark Nudelman
|
|
*
|
|
* You may distribute under the terms of either the GNU General Public
|
|
* License or the Less License, as specified in the README file.
|
|
*
|
|
* For more information, see the README file.
|
|
*/
|
|
|
|
|
|
/*
|
|
* 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 "less.h"
|
|
#include <signal.h>
|
|
#include <setjmp.h>
|
|
#if HAVE_TIME_H
|
|
#include <time.h>
|
|
#endif
|
|
#if HAVE_ERRNO_H
|
|
#include <errno.h>
|
|
#endif
|
|
#if HAVE_VALUES_H
|
|
#include <values.h>
|
|
#endif
|
|
|
|
/*
|
|
* BSD setjmp() saves (and longjmp() restores) the signal mask.
|
|
* This costs a system call or two per setjmp(), so if possible we clear the
|
|
* signal mask with sigsetmask(), and use _setjmp()/_longjmp() instead.
|
|
* On other systems, setjmp() doesn't affect the signal mask and so
|
|
* _setjmp() does not exist; we just use setjmp().
|
|
*/
|
|
#if HAVE__SETJMP && HAVE_SIGSETMASK
|
|
#define SET_JUMP _setjmp
|
|
#define LONG_JUMP _longjmp
|
|
#else
|
|
#define SET_JUMP setjmp
|
|
#define LONG_JUMP longjmp
|
|
#endif
|
|
|
|
public int reading;
|
|
|
|
static jmp_buf read_label;
|
|
|
|
extern int sigs;
|
|
|
|
/*
|
|
* Like read() system call, but is deliberately interruptible.
|
|
* A call to intread() from a signal handler will interrupt
|
|
* any pending iread().
|
|
*/
|
|
public int
|
|
iread(fd, buf, len)
|
|
int fd;
|
|
char *buf;
|
|
unsigned int len;
|
|
{
|
|
register int n;
|
|
|
|
start:
|
|
#if MSDOS_COMPILER==WIN32C
|
|
if (ABORT_SIGS())
|
|
return (READ_INTR);
|
|
#else
|
|
#if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
|
|
if (kbhit())
|
|
{
|
|
int c;
|
|
|
|
c = getch();
|
|
if (c == '\003')
|
|
return (READ_INTR);
|
|
ungetch(c);
|
|
}
|
|
#endif
|
|
#endif
|
|
if (SET_JUMP(read_label))
|
|
{
|
|
/*
|
|
* We jumped here from intread.
|
|
*/
|
|
reading = 0;
|
|
#if HAVE_SIGPROCMASK
|
|
{
|
|
sigset_t mask;
|
|
sigemptyset(&mask);
|
|
sigprocmask(SIG_SETMASK, &mask, NULL);
|
|
}
|
|
#else
|
|
#if HAVE_SIGSETMASK
|
|
sigsetmask(0);
|
|
#else
|
|
#ifdef _OSK
|
|
sigmask(~0);
|
|
#endif
|
|
#endif
|
|
#endif
|
|
return (READ_INTR);
|
|
}
|
|
|
|
flush();
|
|
reading = 1;
|
|
#if MSDOS_COMPILER==DJGPPC
|
|
if (isatty(fd))
|
|
{
|
|
/*
|
|
* Don't try reading from a TTY until a character is
|
|
* available, because that makes some background programs
|
|
* believe DOS is busy in a way that prevents those
|
|
* programs from working while "less" waits.
|
|
*/
|
|
fd_set readfds;
|
|
|
|
FD_ZERO(&readfds);
|
|
FD_SET(fd, &readfds);
|
|
if (select(fd+1, &readfds, 0, 0, 0) == -1)
|
|
return (-1);
|
|
}
|
|
#endif
|
|
n = read(fd, buf, len);
|
|
#if 1
|
|
/*
|
|
* This is a kludge to workaround a problem on some systems
|
|
* where terminating a remote tty connection causes read() to
|
|
* start returning 0 forever, instead of -1.
|
|
*/
|
|
{
|
|
extern int ignore_eoi;
|
|
if (!ignore_eoi)
|
|
{
|
|
static int consecutive_nulls = 0;
|
|
if (n == 0)
|
|
consecutive_nulls++;
|
|
else
|
|
consecutive_nulls = 0;
|
|
if (consecutive_nulls > 20)
|
|
quit(QUIT_ERROR);
|
|
}
|
|
}
|
|
#endif
|
|
reading = 0;
|
|
if (n < 0)
|
|
{
|
|
#if HAVE_ERRNO
|
|
/*
|
|
* Certain values of errno indicate we should just retry the read.
|
|
*/
|
|
#if MUST_DEFINE_ERRNO
|
|
extern int errno;
|
|
#endif
|
|
#ifdef EINTR
|
|
if (errno == EINTR)
|
|
goto start;
|
|
#endif
|
|
#ifdef EAGAIN
|
|
if (errno == EAGAIN)
|
|
goto start;
|
|
#endif
|
|
#endif
|
|
return (-1);
|
|
}
|
|
return (n);
|
|
}
|
|
|
|
/*
|
|
* Interrupt a pending iread().
|
|
*/
|
|
public void
|
|
intread()
|
|
{
|
|
LONG_JUMP(read_label, 1);
|
|
}
|
|
|
|
/*
|
|
* Return the current time.
|
|
*/
|
|
#if HAVE_TIME
|
|
public time_type
|
|
get_time()
|
|
{
|
|
time_type t;
|
|
|
|
time(&t);
|
|
return (t);
|
|
}
|
|
#endif
|
|
|
|
|
|
#if !HAVE_STRERROR
|
|
/*
|
|
* Local version of strerror, if not available from the system.
|
|
*/
|
|
static char *
|
|
strerror(err)
|
|
int err;
|
|
{
|
|
#if HAVE_SYS_ERRLIST
|
|
static char buf[16];
|
|
extern char *sys_errlist[];
|
|
extern int sys_nerr;
|
|
|
|
if (err < sys_nerr)
|
|
return sys_errlist[err];
|
|
sprintf(buf, "Error %d", err);
|
|
return buf;
|
|
#else
|
|
return ("cannot open");
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* errno_message: Return an error message based on the value of "errno".
|
|
*/
|
|
public char *
|
|
errno_message(filename)
|
|
char *filename;
|
|
{
|
|
register char *p;
|
|
register char *m;
|
|
int len;
|
|
#if HAVE_ERRNO
|
|
#if MUST_DEFINE_ERRNO
|
|
extern int errno;
|
|
#endif
|
|
p = strerror(errno);
|
|
#else
|
|
p = "cannot open";
|
|
#endif
|
|
len = (int) (strlen(filename) + strlen(p) + 3);
|
|
m = (char *) ecalloc(len, sizeof(char));
|
|
SNPRINTF2(m, len, "%s: %s", filename, p);
|
|
return (m);
|
|
}
|
|
|
|
/* #define HAVE_FLOAT 0 */
|
|
|
|
static POSITION
|
|
muldiv(val, num, den)
|
|
POSITION val, num, den;
|
|
{
|
|
#if HAVE_FLOAT
|
|
double v = (((double) val) * num) / den;
|
|
return ((POSITION) (v + 0.5));
|
|
#else
|
|
POSITION v = ((POSITION) val) * num;
|
|
|
|
if (v / num == val)
|
|
/* No overflow */
|
|
return (POSITION) (v / den);
|
|
else
|
|
/* Above calculation overflows;
|
|
* use a method that is less precise but won't overflow. */
|
|
return (POSITION) (val / (den / num));
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Return the ratio of two POSITIONS, as a percentage.
|
|
* {{ Assumes a POSITION is a long int. }}
|
|
*/
|
|
public int
|
|
percentage(num, den)
|
|
POSITION num, den;
|
|
{
|
|
return (int) muldiv(num, (POSITION) 100, den);
|
|
}
|
|
|
|
/*
|
|
* Return the specified percentage of a POSITION.
|
|
*/
|
|
public POSITION
|
|
percent_pos(pos, percent, fraction)
|
|
POSITION pos;
|
|
int percent;
|
|
long fraction;
|
|
{
|
|
/* Change percent (parts per 100) to perden (parts per NUM_FRAC_DENOM). */
|
|
POSITION perden = (percent * (NUM_FRAC_DENOM / 100)) + (fraction / 100);
|
|
|
|
if (perden == 0)
|
|
return (0);
|
|
return (POSITION) muldiv(pos, perden, (POSITION) NUM_FRAC_DENOM);
|
|
}
|
|
|
|
#if !HAVE_STRCHR
|
|
/*
|
|
* strchr is used by regexp.c.
|
|
*/
|
|
char *
|
|
strchr(s, c)
|
|
char *s;
|
|
int c;
|
|
{
|
|
for ( ; *s != '\0'; s++)
|
|
if (*s == c)
|
|
return (s);
|
|
if (c == '\0')
|
|
return (s);
|
|
return (NULL);
|
|
}
|
|
#endif
|
|
|
|
#if !HAVE_MEMCPY
|
|
VOID_POINTER
|
|
memcpy(dst, src, len)
|
|
VOID_POINTER dst;
|
|
VOID_POINTER src;
|
|
int len;
|
|
{
|
|
char *dstp = (char *) dst;
|
|
char *srcp = (char *) src;
|
|
int i;
|
|
|
|
for (i = 0; i < len; i++)
|
|
dstp[i] = srcp[i];
|
|
return (dst);
|
|
}
|
|
#endif
|
|
|
|
#ifdef _OSK_MWC32
|
|
|
|
/*
|
|
* This implements an ANSI-style intercept setup for Microware C 3.2
|
|
*/
|
|
public int
|
|
os9_signal(type, handler)
|
|
int type;
|
|
RETSIGTYPE (*handler)();
|
|
{
|
|
intercept(handler);
|
|
}
|
|
|
|
#include <sgstat.h>
|
|
|
|
int
|
|
isatty(f)
|
|
int f;
|
|
{
|
|
struct sgbuf sgbuf;
|
|
|
|
if (_gs_opt(f, &sgbuf) < 0)
|
|
return -1;
|
|
return (sgbuf.sg_class == 0);
|
|
}
|
|
|
|
#endif
|