hush/printutils/lpr.c
Denis Vlasenko 42cc304e90 lpr: add more accurate comments
*: trailing whitespace removal
2008-03-24 02:05:58 +00:00

248 lines
6.9 KiB
C

/* vi: set sw=4 ts=4: */
/*
* bare bones version of lpr & lpq: BSD printing utilities
*
* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
*
* Original idea and code:
* Walter Harms <WHarms@bfs.de>
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*
* See RFC 1179 for protocol description.
*/
#include "libbb.h"
/*
* LPD returns binary 0 on success.
* Otherwise it returns error message.
*/
static void get_response_or_say_and_die(int fd, const char *errmsg)
{
ssize_t sz;
char buf[128];
buf[0] = ' ';
sz = safe_read(fd, buf, 1);
if ('\0' != buf[0]) {
// request has failed
// try to make sure last char is '\n', but do not add
// superfluous one
sz = full_read(fd, buf + 1, 126);
bb_error_msg("error while %s%s", errmsg,
(sz > 0 ? ". Server said:" : ""));
if (sz > 0) {
// sz = (bytes in buf) - 1
if (buf[sz] != '\n')
buf[++sz] = '\n';
safe_write(STDERR_FILENO, buf, sz + 1);
}
xfunc_die();
}
}
int lpqr_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
int lpqr_main(int argc ATTRIBUTE_UNUSED, char *argv[])
{
enum {
OPT_P = 1 << 0, // -P queue[@host[:port]]. If no -P is given use $PRINTER, then "lp@localhost:515"
OPT_U = 1 << 1, // -U username
LPR_V = 1 << 2, // -V: be verbose
LPR_h = 1 << 3, // -h: want banner printed
LPR_C = 1 << 4, // -C class: job "class" (? supposedly printed on banner)
LPR_J = 1 << 5, // -J title: the job title for the banner page
LPR_m = 1 << 6, // -m: send mail back to user
LPQ_SHORT_FMT = 1 << 2, // -s: short listing format
LPQ_DELETE = 1 << 3, // -d: delete job(s)
LPQ_FORCE = 1 << 4, // -f: force waiting job(s) to be printed
};
char tempfile[sizeof("/tmp/lprXXXXXX")];
const char *job_title;
const char *printer_class = ""; // printer class, max 32 char
const char *queue; // name of printer queue
const char *server = "localhost"; // server[:port] of printer queue
char *hostname;
// N.B. IMHO getenv("USER") can be way easily spoofed!
const char *user = bb_getpwuid(NULL, -1, getuid());
unsigned job;
unsigned opts;
int fd;
// parse options
// TODO: set opt_complementary: s,d,f are mutually exclusive
opts = getopt32(argv,
(/*lp*/'r' == applet_name[2]) ? "P:U:VhC:J:m" : "P:U:sdf"
, &queue, &user
, &printer_class, &job_title
);
argv += optind;
// if queue is not specified -> use $PRINTER
if (!(opts & OPT_P))
queue = getenv("PRINTER");
// if queue is still not specified ->
if (!queue) {
// ... queue defaults to "lp"
// server defaults to "localhost"
queue = "lp";
// if queue is specified ->
} else {
// queue name is to the left of '@'
char *s = strchr(queue, '@');
if (s) {
// server name is to the right of '@'
*s = '\0';
server = s + 1;
}
}
// do connect
fd = create_and_connect_stream_or_die(server, 515);
//
// LPQ ------------------------
//
if (/*lp*/'q' == applet_name[2]) {
char cmd;
// force printing of every job still in queue
if (opts & LPQ_FORCE) {
cmd = 1;
goto command;
// delete job(s)
} else if (opts & LPQ_DELETE) {
fdprintf(fd, "\x5" "%s %s", queue, user);
while (*argv) {
fdprintf(fd, " %s", *argv++);
}
bb_putchar('\n');
// dump current jobs status
// N.B. periodical polling should be achieved
// via "watch -n delay lpq"
// They say it's the UNIX-way :)
} else {
cmd = (opts & LPQ_SHORT_FMT) ? 3 : 4;
command:
fdprintf(fd, "%c" "%s\n", cmd, queue);
bb_copyfd_eof(fd, STDOUT_FILENO);
}
return EXIT_SUCCESS;
}
//
// LPR ------------------------
//
if (opts & LPR_V)
bb_error_msg("connected to server");
job = getpid() % 1000;
hostname = safe_gethostname();
// no files given on command line? -> use stdin
if (!*argv)
*--argv = (char *)"-";
fdprintf(fd, "\x2" "%s\n", queue);
get_response_or_say_and_die(fd, "setting queue");
// process files
do {
int dfd;
struct stat st;
char *c;
char *remote_filename;
char *controlfile;
// if data file is stdin, we need to dump it first
if (LONE_DASH(*argv)) {
strcpy(tempfile, "/tmp/lprXXXXXX");
dfd = mkstemp(tempfile);
if (dfd < 0)
bb_perror_msg_and_die("mkstemp");
bb_copyfd_eof(STDIN_FILENO, dfd);
xlseek(dfd, 0, SEEK_SET);
*argv = (char*)bb_msg_standard_input;
} else {
dfd = xopen(*argv, O_RDONLY);
}
/* "The name ... should start with ASCII "cfA",
* followed by a three digit job number, followed
* by the host name which has constructed the file."
* We supply 'c' or 'd' as needed for control/data file. */
remote_filename = xasprintf("fA%03u%s", job, hostname);
// create control file
// TODO: all lines but 2 last are constants! How we can use this fact?
controlfile = xasprintf(
"H" "%.32s\n" "P" "%.32s\n" /* H HOST, P USER */
"C" "%.32s\n" /* C CLASS - printed on banner page (if L cmd is also given) */
"J" "%.99s\n" /* J JOBNAME */
/* "class name for banner page and job name
* for banner page commands must precede L command" */
"L" "%.32s\n" /* L USER - print banner page, with given user's name */
"M" "%.32s\n" /* M WHOM_TO_MAIL */
"l" "d%.31s\n" /* l DATA_FILE_NAME ("dfAxxx") */
, hostname, user
, printer_class /* can be "" */
, ((opts & LPR_J) ? job_title : *argv)
, (opts & LPR_h) ? user : ""
, (opts & LPR_m) ? user : ""
, remote_filename
);
// delete possible "\nX\n" patterns
c = controlfile;
while ((c = strchr(c, '\n')) != NULL) {
c++;
while (c[0] && c[1] == '\n')
memmove(c, c+2, strlen(c+1)); /* strlen(c+1) == strlen(c+2) + 1 */
}
// send control file
if (opts & LPR_V)
bb_error_msg("sending control file");
/* "Once all of the contents have
* been delivered, an octet of zero bits is sent as
* an indication that the file being sent is complete.
* A second level of acknowledgement processing
* must occur at this point." */
fdprintf(fd, "\x2" "%u c%s\n" "%s" "%c",
(unsigned)strlen(controlfile),
remote_filename, controlfile, '\0');
get_response_or_say_and_die(fd, "sending control file");
// send data file, with name "dfaXXX"
if (opts & LPR_V)
bb_error_msg("sending data file");
st.st_size = 0; /* paranoia: fstat may theoretically fail */
fstat(dfd, &st);
fdprintf(fd, "\x3" "%"OFF_FMT"u d%s\n", st.st_size, remote_filename);
if (bb_copyfd_size(dfd, fd, st.st_size) != st.st_size) {
// We're screwed. We sent less bytes than we advertised.
bb_error_msg_and_die("local file changed size?!");
}
write(fd, "", 1); // send ACK
get_response_or_say_and_die(fd, "sending data file");
// delete temporary file if we dumped stdin
if (*argv == (char*)bb_msg_standard_input)
unlink(tempfile);
// cleanup
close(fd);
free(remote_filename);
free(controlfile);
// say job accepted
if (opts & LPR_V)
bb_error_msg("job accepted");
// next, please!
job = (job + 1) % 1000;
} while (*++argv);
return EXIT_SUCCESS;
}