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/* $Id: spoolpipe.c 12590 2015-01-03 13:53:52Z sshwarts $
*
* spoolpipe.c
* by Carl Sopchak
*
* Read a pipe that stays open, send the data to a temp file. Print
* the temp file if no new input data is seen within a period of time. This
* is useful, e.g., to create separate spool files without exiting a program
* that doesn't close it's printer output file.
*
* ---------------------------------------------------------------------------
*
* Copyright (c) 2002 Cegis Enterprises, Inc. Syracuse, NY 13215
*
* ---------------------------------------------------------------------------
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* --------------------------------------------------------------------------
* Modification log:
*
* 2002/05/20 - Initial programming
*
* --------------------------------------------------------------------------
*/
#define BUF_SIZE 4*1024
#define DEBUG 0
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
int infd, outfd;
int delay = 60; // default delay, in seconds
int count_down = 0;
char buffer[BUF_SIZE];
ssize_t readcnt, writecnt;
int didwait = 0; // have we already waited?
int havedata = 0; // have we read anything in?
int q;
pid_t pid, wait_pid;
int wait_status;
int main (int argc, char *argv[]) {
#if DEBUG
printf("Command line arguments (%d):\n", argc);
for (q = 0; q < argc ; q++) {
printf(" %d = %s\n", q, argv[q]);
}
#endif
if ((argc < 3) || (argc > 4)) {
printf("usage: %s <inpipe> <tempfilename> [<maxdelay>]\n", argv[0]);
exit(1);
}
if (argc == 4) { // get delay
delay = strtol(argv[3], (char **) NULL, 10);
if (delay < 0) {
printf("Unable to convert maximum delay value: %s\n", argv[3]);
exit(2);
}
} // get delay
#if DEBUG
printf("Delay is set to %d seconds.\n", delay);
#endif
infd = open(argv[1], O_RDONLY | O_NONBLOCK);
if (infd == -1) {
printf("Error opening input pipe %s: %d - %s\n", argv[1], errno, strerror(errno));
exit(3);
}
outfd = open(argv[2], O_RDWR | O_CREAT | O_TRUNC, S_IRWXU);
if (outfd == -1) {
printf("Error opening output file %s: %d - %s\n", argv[2], errno, strerror(errno));
exit(4);
}
count_down = delay;
while (1) { // must kill with a signal....
readcnt = read(infd, buffer, (size_t) BUF_SIZE);
#if DEBUG
printf("read() returned with readcnt = %d, errno = %d\n", readcnt, errno);
#endif
if ((readcnt == -1) && (errno != EAGAIN)) { // EAGAIN - no data waiting, can ignore
printf("Error reading input pipe: %d - %s\n", errno, strerror(errno));
exit(5);
} else { // no errors reading input pipe
if (readcnt > 0) {
writecnt = write(outfd, buffer, readcnt);
if (writecnt == -1) {
printf("Error writing output file: %d - %s\n", errno, strerror(errno));
exit(6);
}
didwait = 0; // reset wait flag (wait again)
count_down = delay;
havedata = 1; // set flag that we got some data
} else { //readcnt must = 0
if (!didwait) { //have not waited yet...
if (count_down > 0) { // sleep a bit
sleep(1);
count_down -= 1;
} else {
didwait = 1; // set wait flag (don't wait again)
}
} else { // already waited
if (havedata) { // have data to print, close & reopen output file
if (close(outfd) != 0) {
printf("Error closing output file: %d - %s\n", errno, strerror(errno));
exit(7);
}
#if DEBUG
printf("Spooling temp file...\n");
#endif
pid = fork();
if (pid == -1) {
printf("Error forking new process: %d - %s\n", errno, strerror(errno));
exit(9);
}
if (pid == 0) { // we're now running in the child process...
execlp("lpr", "lpr", argv[2], NULL);
exit(99); // should never get here...
} // we're now running in the child process...
if (pid > 0) { // we're running in the parent process...
wait_pid = waitpid(pid, (int *)&wait_status, 0);
if (wait_pid != pid) { // some sort of error
printf("Wait for 'lpr' command returned abnormally!\n");
if (WIFEXITED(wait_status)) {
printf(" 'lpr' exited normally.\n");
} else {
printf(" 'lpr' exited abnormally, return code = %d.\n", WEXITSTATUS(wait_status));
}
if (WIFSIGNALED(wait_status)) {
printf(" 'lpr' received uncaught signal %d\n", WTERMSIG(wait_status));
}
} // some sort of error
} // we're running in the parent process...
outfd = open(argv[2], O_RDWR | O_TRUNC);
if (outfd == -1) {
printf("Error re-opening output file: %d - %s\n", errno, strerror(errno));
exit(8);
}
} // have data to print, close & repoen output file.
havedata = 0; // no more data waiting
count_down = delay;
didwait = 0; // reset wait flag (wait again)
} // already waited
} // readcnt must = 0
} // no errors reading input pipe
} // must kill with a signal...
exit(0);
} // eof(spoolpipe.c)
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