new applets lpr,lpq (update)

[Denys Vlasenko]

On Monday 21 July 2008 12:57, Klaus.Hachmeister at l-3com.com wrote:
> Shure,
> 
> now the output of /etc/syslog (serverside) is differrent. (but still no
> printing)
> 
> ----------------------------------------------------------------------
> 
> /etc/syslog
> 
> Jul 21 12:44:36 PC535li cups-lpd[11071]: Connection from blackfin (IPv4
> 192.168.70.120)
> Jul 21 12:44:36 PC535li cups-lpd[11071]: Receive print job for psprint
> Jul 21 12:44:36 PC535li cups-lpd[11071]: Error while reading file -
> Connection reset by peer
> Jul 21 12:44:36 PC535li cups-lpd[11071]: Closing connection

> Jul 21 12:45:24 PC535li cups-lpd[11072]: Connection from blackfin (IPv4
> 192.168.70.120)
> Jul 21 12:45:24 PC535li cups-lpd[11072]: Receive print job for psprint
> Jul 21 12:45:48 PC535li cups-lpd[11072]: Print file - job ID = 91
> Jul 21 12:45:48 PC535li cups-lpd[11072]: Closing connection

One printing was ok (second one), another failed.

> / # lpr
> -Ppsprint at lpdserver /mnt/nfs/testpage.ps                                                                                                            
> / # strace -f -v -s 1024  lpr
> -Ppsprint at lpdserver /mnt/nfs/testpage.ps                                                                                      
> ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {c_iflags=0x500, c_oflags=0x5,
> c_cflags=0x1cb1, c_lflags=0x8a3b, c_line=0, c_cc="\x03\x1c\x08\x15\x04
> \x00\x01\x00\x0
...
...

I find it very pleasant to spend 15 minutes unwrapping the strace,
removing extra spaces and the like. However note that some other
developers may have less perverted methods of having fun, and may
resort to simple entertainments like beating the email's author
with big stick. :)

Let's take a look.


# strace -f -v -s 1024 lpr -Ppsprint at lpdserver /mnt/nfs/testpage.ps
ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {c_iflags=0x500, c_oflags=0x5, c_cflags=0x1cb1, c_lflags=0x8a3b, c_line=0, c_cc="\x03\x1c\x08\x15\x04\x00\x01\x00\x0
ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, {c_iflags=0x500, c_oflags=0x5, c_cflags=0x1cb1, c_lflags=0x8a3b, c_line=0, c_cc="\x03\x1c\x08\x15\x04\x00\x01\x00\x0
...
close(3)                                = 0

nothing interesting above.

socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
connect(3, {sa_family=AF_INET, sin_port=htons(515), sin_addr=inet_addr("192.168.70.12")}, 16) = 0

We opened a TCP connection to 192.168.70.12:515.

getpid()                                = 260
uname({sysname="Linux", nodename="blackfin", release="2.6.22.18-ADI-2008R1-svn", version="#60 Fri Jul 18 13:39:32 CEST 2008", machine="blackfin"}) = 0
write(3, "\2psprint\n", 9)              = 9

We say "I want to print to queue 'psprint'".

read(3, "\0", 1)                        = 1

Server says "ok"

open("/mnt/nfs/testpage.ps", O_RDONLY)  = 4
write(3, "\00254 cfA260blackfin\n", 19) = 19

We say "here goes the controlfile" (\002)
"of 54 bytes" (54) "named cfA260blackfin"

write(3, "Hblackfin\nProot\nJ/mnt/nfs/testpage.ps\nldfA260blackfin\n", 54) = 54

We send controlfile contents:
"H<host>\n", "P<user>\n", "J<jobname>\n" "l<datafilename>\n"

write(3, "\0", 1)                       = 1

We say "is it ok"?

read(3, "\0", 1)                        = 1

server says "ok"

fstat(4, {st_dev=makedev(0, 15), st_ino=696322, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=8192, st_blocks=520, st_size=260183, st_at0
write(3, "\003260183 dfA260blackfin\n", 23) = 23

We say "here is a datafile, 260183 bytes, named dfA260blackfin"

read(4, "%!PS-Adobe-2.0\n%%Title: testpage.fig\n%%Creator: fig2dev Version 3.2 Patchlevel 3d\n%%CreationDate: Mon Dec  3 11:54:07 2001\n%%For: papowell at h116
write(3, "%!PS-Adobe-2.0\n%%Title: testpage.fig\n%%Creator: fig2dev Version 3.2 Patchlevel 3d\n%%CreationDate: Mon Dec  3 11:54:07 2001\n%%For: papowell at h16
read(4, "Bold ff 150.00 scf sf\n5700 7800 m\ngs 1 -1 sc (Gold) dup swpop 2 div neg 0 rm  col-1 sh gr\n/Helvetica-Bold ff 150.00 scf sf\n69007800 m\ngs 1 6
write(3, "Bold ff 150.00 scf sf\n5700 7800 m\ngs 1 -1 sc (Gold) dup swpop 2 div neg 0 rm  col-1 sh gr\n/Helvetica-Bold ff 150.00 scf sf\n69007800 m\ngs 16
...
read(4, "00dfff4e4a4e\n009b004e003d024e003d0e4e029b034e005e009b354e\nrestore grestore\n%\n% End Imported PIC File: LPRngT-L.gif\n%\n/Times-Roman ff 180.00 5
write(3, "00dfff4e4a4e\n009b004e003d024e003d0e4e029b034e005e009b354e\nrestore grestore\n%\n% End Imported PIC File: LPRngT-L.gif\n%\n/Times-Roman ff 180.005

we sent the file

write(3, "\0", 1)                       = 1

We say "is it ok"?

read(3, "\0", 1)                        = 1

server says "ok"

close(3)                                = 0
_exit(0)

we exit.



What confuses me here is that it looks like server was totally happy
and actually accepted the job. I suspect you sent a strace of
successful lpr.

--
vda