Interdata732/usr/source/lpd_melb/lpd.c
/*
* Line printer daemon
*
* Modified by Kenj McDonell, 14 April 1978
*
*/
/* File names */
char lpd[] "/u/usr/lpd"; /* spooler directory */
char lock[] "/u/usr/lpd/lock"; /* existence of this file prevents multiple, concurrent daemons */
char printer[] "/dev/pr";
char kill[] "/u/usr/lpd/kill"; /* kill/restart/pause/continue current job flag */
char jobf[] "/u/usr/lpd/job"; /* current spool job no. written here */
char tty[] "/dev/tty?"; /* spool job owner's terminal */
char amesg[] "Spool job no. XXXXX aborted";
char rmesg[] "Spool job no. XXXXX restarted";
/* Buffers */
int cmdbuf[131]; /* for reading command file */
char prbuf[512]; /* for copying file to printer */
char lbuf[64]; /* for assembling lines from command file */
char dbuf[17]; /* for reading directory */
char killbuf[8]; /* commands from opctl */
char person[20]; /* login user name */
char now[2]; /* used to fetch current time */
char daytime[30]; /* date and time string */
char banner[10]; /* banner heading string */
char mesg[31]; /* end of job message to user */
char submitted[30]; /* date and time submitted */
char realfname[64]; /* real spooled file name */
char ttyno; /* tty no. spool job submitted from */
int debug; /* debug flag */
main()
{
register flag;
extern int fout;
int fd;
/* Ignore quit, interrupt, hangup */
signal(1, 1);
signal(2, 1);
signal(3, 1);
/* Use lock to prevent multiple active daemons */
if (creat(lock, 0) < 0)
exit(0);
/* Fork and exit, thus spawning the daemon and letting opr terminate */
if (fork())
exit(0);
/* Before opening the printer, make sure there's something to print */
close(0);
close(1);
close(2);
/*
* assumes following file descriptor assignments will occur OK
* 0 - spool directory
* 1 - printer
*/
if (open(lpd, 0) != 0)
dexit();
flag = 0;
while (read(0, dbuf, 16) == 16)
if ((dbuf[0] | dbuf[1]) != 0
&& dbuf[2] == 'd' && dbuf[3] == 'f')
flag++;
if (!flag)
dexit();
/* Open the printer */
if (open(printer, 1) != 1)
dexit();
dup(1);
fout = dup(1);
/* Search lpd directory for work to do */
if (chdir(lpd) < 0)
dexit();
seek(0, 0, 0);
while (read(0, dbuf, 16) == 16) {
if ((dbuf[0] | dbuf[1]) == 0
|| dbuf[2] != 'd' || dbuf[3] != 'f')
continue;
/*
* Process one command file.
* First write the spool job number into "jobf".
*/
if ((fd = creat(jobf, 0666)) != -1) {
write (fd, &dbuf[5], 5);
write (fd, "\n", 1);
}
spool(&dbuf[2]);
/*
* All done, now remove the job no. and command files
*/
close (fd);
unlink(jobf);
unlink(&dbuf[2]);
/* Reread directory in case it changed while we were spooling */
seek(0, 0, 0);
}
dexit();
}
/*
* Remove job no. and lock files, and terminate
*/
dexit()
{
unlink(jobf);
unlink(lock);
exit(0);
}
/*
* Read and obey a file of spooling commands
*/
spool(dfname)
char *dfname;
{
register in, len, c;
int job, copies, copyno;
int bcopies, j, n;
char *p, *q;
/*
* All the work is really done in here
*/
if (fopen(dfname, cmdbuf) < 0)
return;
/*
* Now the command file has been successfully opened,
* initialize all relvant strings and flags, then
* process the commands serially.
*/
job = atoi(&dbuf[5]);
copies = 1;
bcopies = 1;
banner[0] = '\0';
mesg[0] = '\0';
person[0] = '\0';
submitted[0] = '\0';
realfname[0] = '\0';
ttyno = '\0';
debug = 0;
/* fetch and process commands */
for(;;) {
switch (c = getc(cmdbuf)) {
/* banner */
case 'B':
getline(banner);
continue;
/* set debug flag */
case 'D':
debug = 1;
continue;
/* output a file */
case 'F':
getline(lbuf);
if ((in = open(lbuf, 0)) < 0) continue;
if (debug) {
printf ("job: %l\n", job);
printf ("person: %s\n", person);
printf("ttyno: %c\n", ttyno);
printf ("real file: %s\n", realfname);
printf ("banner: %s\n", banner);
printf ("banner copies: %l\n", bcopies);
printf ("submitted: %s\n", submitted);
printf ("released: %s\n", daytime);
printf ("copies: %l\n", copies);
}
for (copyno = 1; copyno <= copies; copyno++) {
goto newcopy;
restart:
/* current job has been restarted */
p = &dbuf[5];
q = &rmesg[14];
while (*q++ = *p++);
*--q = ' ';
sendmesg(person, ttyno, rmesg);
printf("\n\n* * * Spool Job Restarted * * *\n");
newcopy:
time(now);
p = daytime;
q = ctime(now);
while ((*p++ = *q++) != '\n');
*--p = '\0';
for (j = 0; j < bcopies; j++) {
bannerpage(job, copyno, copies);
if ((n = check(job)) != 0) {
/* opctl has given us the word */
if (n == 1) goto restart;
goto killed;
}
}
/* flush the buffer before copying */
flush();
/* the output is done here */
seek (in, 0, 0);
while ((len = read(in, prbuf, 512)) > 0
&& write(1, prbuf, len) == len)
if ((n = check(job)) != 0) {
/* opctl has decreed that we restart or abort */
if (n == 1) goto restart;
/* woops .. abandon the current output file */
killed:
p = &dbuf[5];
q = &amesg[14];
while (*q++ = *p++);
*--q = ' ';
sendmesg(person, ttyno, amesg);
printf("\n\n* * * Spool Job Aborted * * *\n");
copyno = copies;
break;
}
/* eject the last page */
putchar('\014');
}
close(in);
continue;
/* login user id */
case 'L':
getline(person);
continue;
/* end of job message */
case 'M':
getline(mesg);
continue;
/* number of copies */
case 'N':
getline(lbuf);
copies = atoi(lbuf);
continue;
/* real file name */
case 'R':
getline(realfname);
continue;
/* time submitted */
case 'S':
getline(submitted);
continue;
/* tty no. */
case 'T':
getline(lbuf);
ttyno = lbuf[0];
continue;
/* number of banner pages per copy */
case 'X':
getline(lbuf);
bcopies = atoi(lbuf);
continue;
/* Delete file after copying */
case 'U':
getline(lbuf);
unlink(lbuf);
continue;
/* end of command file */
case -1:
close(cmdbuf[0]);
flush();
sendmesg(person, ttyno, mesg);
return;
/* unidentified command */
default:
getline(lbuf);
/* just ignore it */
continue;
}
}
close(cmdbuf[0]);
}
/*
* Read rest of line from command file
*/
getline(buf)
char buf[];
{
register char *p;
register c;
for (p = buf; (*p = c = getc(cmdbuf)) != '\n' && c > 0; p++)
;
*p = '\0';
}
bannerpage(job, copyno, copies)
int job, copyno, copies;
{
int j;
char c;
register char *p, *q;
/*
* Output the banner page headings.
*/
putchar('\014');
p = realfname;
q = realfname;
while (c = *q++) if (c == '/') p = q;
/* 'p' points past the last '/' */
q = q-1;
/* 'q' points at the end of the string */
if (q > p+9) {
/* truncate from right */
q = p+9;
*q = '\0';
} else
if (q < p+9) {
/* extend to the left */
p = q-9;
if (p < realfname) p = realfname;
}
q = banner;
if (*p != '\0') bprint(p);
else if (*q != '0') bprint(q);
else printf (".\n\n\n\n\n\n\n\n\n\n\n\n\n");
chars(' ');
chars('!');
chars('"');
printf ("\n\n");
printf ("Computer Science Department, Melbourne University\n\n");
printf ("\t\tSpool Job Number: %l\n", job);
printf ("\t\tSubmitted: %s\n\t\tReleased: %s\n", submitted, daytime);
printf ("\t\tCopy %l of %l\n\n\n", copyno, copies);
chars('#');
chars('$');
chars('%');
printf("\n\n");
/* print the banner if it did not appear at the top of the page */
if (*p != '\0' && *q != '\0') bprint(q);
putchar('\014');
return;
}
check(job)
int job;
{
/*
* Check if opctl has sent us a message
*/
int fd, paused, killjob;
paused = 0;
again:
if ((fd = open(kill, 0)) != -1) {
/* "kill" file exists */
read(fd, killbuf, 6);
killjob = atoi(killbuf);
/* get rid of the file */
close(fd);
unlink(kill);
if (killjob == job) {
/* this is really meant for me! */
/* the following control functions are supported :-
* 'p' pause the cUrrent job
* 'a' abort the current job
* 'c' continue the current job
* 'r' restart the current job
*/
switch (killbuf[5]) {
/* pause */
case 'p':
paused = 1;
break;
/* abort */
case 'a':
/* abort this print file */
return(-1);
/* continue */
case 'c':
return(0);
/* restart */
case 'r':
return(1);
}
}
/* note: if "kill" does not refer to the current spool job, ignore it */
}
/* is paused, wait for 5 seconds and try again, else return */
if (paused) {
sleep(5);
paused++;
if (paused < 24) goto again;
/* waited too long ... abort him */
return(-1);
}
return(0);
}
chars(c)
char c;
{
/*
* Print a line of 128 characters, starting with 'c'
*/
int j;
char ch;
ch = c;
for (j = 0; j < 128; j++) {
putchar(ch++);
if (ch > '~') ch = ' ';
}
putchar('\n');
}
sendmesg(loginid, ttyno, message)
char loginid[];
char ttyno;
char message[];
{
/*
* Send a message to a user
*/
int fd, len;
register char *p, *q;
if (ttyno == 'x') return;
if (message[0] != '\0' && (fd = open("/etc/utmp", 0)) != -1) {
/* something to do */
while ((len = read(fd, lbuf, 24)) == 24)
if (lbuf[0] != '\0') {
p = loginid;
q = lbuf;
while (*p++ == *q++);
if (*--p == '\0' && lbuf[8] == ttyno) {
tty[8] = lbuf[8];
close(fd);
if ((fd = open(tty,1)) != -1) {
p = message;
while (*p != '\0') write (fd, p++, 1);
write (fd, "\n", 1);
close(fd);
}
return;
}
}
close(fd);
}
return;
}