/* $NetBSD: os.c,v 1.9 2016/01/26 16:04:12 christos Exp $ */ /* * Copyright (c) 1988 Mark Nudelman * Copyright (c) 1988, 1993 * The 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. 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. */ #include <sys/cdefs.h> #ifndef lint #if 0 static char sccsid[] = "@(#)os.c 8.1 (Berkeley) 6/6/93"; #else __RCSID("$NetBSD: os.c,v 1.9 2016/01/26 16:04:12 christos Exp $"); #endif #endif /* not lint */ /* * Operating system dependent routines. * * Most of the stuff in here is based on Unix, but an attempt * has been made to make things work on other operating systems. * This will sometimes result in a loss of functionality, unless * someone rewrites code specifically for the new operating system. * * The makefile provides defines to decide whether various * Unix features are present. */ #include <sys/param.h> #include <sys/stat.h> #include <sys/file.h> #include <signal.h> #include <setjmp.h> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include "less.h" #include "extern.h" #include "pathnames.h" int reading; static jmp_buf read_label; /* * Pass the specified command to a shell to be executed. * Like plain "system()", but handles resetting terminal modes, etc. */ void lsystem(cmd) char *cmd; { int inp; char cmdbuf[256]; char *shell; /* * Print the command which is to be executed, * unless the command starts with a "-". */ if (cmd[0] == '-') cmd++; else { lower_left(); clear_eol(); putstr("!"); putstr(cmd); putstr("\n"); } /* * De-initialize the terminal and take out of raw mode. */ deinit(); flush(); raw_mode(0); /* * Restore signals to their defaults. */ init_signals(0); /* * Force standard input to be the terminal, "/dev/tty", * even if less's standard input is coming from a pipe. */ inp = dup(0); (void)close(0); if (open(_PATH_TTY, O_RDONLY, 0) < 0) (void)dup(inp); /* * Pass the command to the system to be executed. * If we have a SHELL environment variable, use * <$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 { (void)snprintf(cmdbuf, sizeof(cmdbuf), "%s -c \"%s\"", shell, cmd); cmd = cmdbuf; } } if (*cmd == '\0') cmd = "sh"; (void)system(cmd); /* * Restore standard input, reset signals, raw mode, etc. */ (void)close(0); (void)dup(inp); (void)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(SIGWINCH); #endif } /* * Like read() system call, but is deliberately interruptable. * A call to intread() from a signal handler will interrupt * any pending iread(). */ int iread(fd, buf, len) int fd; char *buf; int len; { 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); } void intread() { (void)sigsetmask(0L); longjmp(read_label, 1); } /* * 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. */ char * glob(filename) char *filename; { FILE *f; char *p; int ch; char *cmd; static char buffer[MAXPATHLEN]; 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>. */ asprintf(&cmd, "echo \"%s\"", filename); if (cmd == NULL) return (filename); } else { /* * Read the output of <$SHELL -c "echo filename">. */ asprintf(&cmd, "%s -c \"echo %s\"", p, filename); if (cmd == NULL) return (filename); } if ((f = popen(cmd, "r")) == NULL) { free(cmd); 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'; (void)pclose(f); return(buffer); } char * bad_file(filename, message, len) char *filename, *message; u_int len; { struct stat statbuf; if (stat(filename, &statbuf) < 0) { (void)snprintf(message, len, "%s: %s", filename, strerror(errno)); return(message); } if ((statbuf.st_mode & S_IFMT) == S_IFDIR) { static char is_dir[] = " is a directory"; strtcpy(message, filename, (int)(len-sizeof(is_dir)-1)); (void)strlcat(message, is_dir, len); return(message); } return((char *)NULL); } /* * Copy a string, truncating to the specified length if necessary. * Unlike strncpy(), the resulting string is guaranteed to be null-terminated. */ void strtcpy(to, from, len) char *to, *from; int len; { (void)strncpy(to, from, (int)len); to[len-1] = '\0'; }
