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/*
* 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 <stdio.h>
#include <signal.h>
#include <setjmp.h>
#include "less.h"
char *getenv();
public int reading;
extern int screen_trashed;
static jmp_buf read_label;
/*
* Pass the specified command to a shell to be executed.
* Like plain "system()", but handles resetting terminal modes, etc.
*/
public 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);
close(0);
if (open("/dev/tty", 0) < 0)
dup(inp);
/*
* Pass the command to the system to be executed.
* If we have a SHELL environment variable, use
* <$SHELL -c "command"> instead of just <command>.
* If the command is empty, just invoke a shell.
*/
if ((shell = getenv("SHELL")) != NULL && *shell != '\0')
{
if (*cmd == '\0')
cmd = shell;
else
{
sprintf(cmdbuf, "%s -c \"%s\"", shell, cmd);
cmd = cmdbuf;
}
}
if (*cmd == '\0')
cmd = "sh";
system(cmd);
/*
* Restore standard input, reset signals, raw mode, etc.
*/
close(0);
dup(inp);
close(inp);
init_signals(1);
raw_mode(1);
init();
screen_trashed = 1;
#if defined(SIGWINCH) || defined(SIGWIND)
/*
* Since we were ignoring window change signals while we executed
* the system command, we must assume the window changed.
*/
winch();
#endif
}
/*
* Like read() system call, but is deliberately interruptable.
* A call to intread() from a signal handler will interrupt
* any pending iread().
*/
public int
iread(fd, buf, len)
int fd;
char *buf;
int len;
{
register int n;
if (setjmp(read_label))
/*
* We jumped here from intread.
*/
return (READ_INTR);
flush();
reading = 1;
n = read(fd, buf, len);
reading = 0;
if (n < 0)
return (-1);
return (n);
}
public void
intread()
{
#if SIGSETMASK
sigsetmask(0);
#endif
longjmp(read_label, 1);
}
#if GET_TIME
public long
get_time()
{
long t;
time(&t);
return (t);
}
#endif
/*
* Expand a filename, substituting any environment variables, etc.
* The implementation of this is necessarily very operating system
* dependent. This implementation is unabashedly only for Unix systems.
*/
#if GLOB
FILE *popen();
public char *
glob(filename)
char *filename;
{
FILE *f;
char *p;
int ch;
char *cmd;
static char buffer[FILENAME];
if (filename[0] == '#')
return (filename);
/*
* We get the shell to expand the filename for us by passing
* an "echo" command to the shell and reading its output.
*/
p = getenv("SHELL");
if (p == NULL || *p == '\0')
{
/*
* Read the output of <echo filename>.
*/
cmd = calloc(strlen(filename)+8, sizeof(char));
if (cmd == NULL)
return (filename);
sprintf(cmd, "echo \"%s\"", filename);
} else
{
/*
* Read the output of <$SHELL -c "echo filename">.
*/
cmd = calloc(strlen(p)+12);
if (cmd == NULL)
return (filename);
sprintf(cmd, "%s -c \"echo %s\"", p, 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';
pclose(f);
return (buffer);
}
#else
public char *
glob(filename)
char *filename;
{
return (filename);
}
#endif
/*
* Returns NULL if the file can be opened and
* is an ordinary file, otherwise an error message
* (if it cannot be opened or is a directory, etc.)
*/
#if STAT
#include <sys/types.h>
#include <sys/stat.h>
public char *
bad_file(filename, message, len)
char *filename;
char *message;
unsigned int len;
{
struct stat statbuf;
if (stat(filename, &statbuf) < 0)
return (errno_message(filename, message, len));
if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
{
static char is_dir[] = " is a directory";
strtcpy(message, filename, len-sizeof(is_dir)-1);
strcat(message, is_dir);
return (message);
}
if ((statbuf.st_mode & S_IFMT) != S_IFREG)
{
static char not_reg[] = " is not a regular file";
strtcpy(message, filename, len-sizeof(not_reg)-1);
strcat(message, not_reg);
return (message);
}
return (NULL);
}
#else
public char *
bad_file(filename, message, len)
char *filename;
char *message;
unsigned int len;
{
return (NULL);
}
#endif
/*
* errno_message: Return an error message based on the value of "errno".
* okreadfail: Return true if the previous failure of a read
* (on the input tty) should be considered ok.
*/
#if PERROR
extern char *sys_errlist[];
extern int sys_nerr;
extern int errno;
public char *
errno_message(filename, message, len)
char *filename;
char *message;
unsigned int len;
{
char *p;
char msg[16];
if (errno < sys_nerr)
p = sys_errlist[errno];
else
{
sprintf(msg, "Error %d", errno);
p = msg;
}
strtcpy(message, filename, len-strlen(p)-3);
strcat(message, ": ");
strcat(message, p);
return (message);
}
#else
public char *
errno_message(filename, message, len)
char *filename;
char *message;
unsigned int len;
{
static char msg[] = ": cannot open";
strtcpy(message, filename, len-sizeof(msg)-1);
strcat(message, msg);
return (message);
}
#endif
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.