bug#56843: grep mangling lines

[David G. Pickett]

That was a bit funny and not an exact reproduction, as <<EOF expands shell 
things.
I did this to see if grep was at fault.  Apparently it is the terminal!  Any 
clues on how I got an xterm to mess up?  (My crontab continues to morph.  My 
trussxx is a strace with options and vi wrapper, evolved since i left Solaris 
and its 'truss'.):


$ crontab -l|(sleep 2 ; grep clam)& trussxx -p $![1] 23978strace: Process 23978 
attachedstrace: Process 23985 attached30 23 * * * /usr/bin/freshclam 
--datadir=/home/dgp/.clamtk/db --log=/home/dgp/.clamtk/db/freshclam.$(/bin/date 
+\%b-\%d-\%Y).log >/home/dgp/.clamtk/db/freshcla_cron.log 2>&1 ; 
/usr/local/bin/clamdscan --reload --log="$HOME/.clamtk/history/$(/bin/date 
+\%b-\%d-\%Y).log" >>.clamtk/history/clamscan.log 2>&1 ; if [ `fuser 
.clamtk/history/clamscan.log 2>/dev/null` = "" ]; then  echo Still running 
>>.clamtk/history/clamscan.log ; else  /usr/local/bin/clamdscan --quiet 
--multiscan --fdpass --log="$HOME/.clamtk/history/$(/bin/date 
+\%b-\%d-\%Y).log" / >>.clamtk/history/clamscan.log 2>&1 ; fi # freshclam 
update and clam-scan
===================================
23985 write(1, "30 23 * * * /usr/bin/fresh\33[01;31m\33[Kclam\33[m\33[K 
--datadir=/home/dgp/.\33[01;31m\33[Kclam\33[m\33[Ktk/db 
--log=/home/dgp/.\33[01;31m\33[Kclam\33[m\33[Ktk/db/fresh\33[01;31m\33[Kclam\33[m\33[K.$(/bin/date
 +\\%b-\\%d-\\%Y).log 
>/home/dgp/.\33[01;31m\33[Kclam\33[m\33[Ktk/db/fresh\33[01;31m\33[Kclam\33[m\33[K_cron.log
 2>&1 ; /usr/local/bin/\33[01;31m\33[Kclam\33[m\33[Kdscan --reload 
--log=\"$HOME/.\33[01;31m\33[Kclam\33[m\33[Ktk/history/$(/bin/date 
+\\%b-\\%d-\\%Y).log\" 
>>.\33[01;31m\33[Kclam\33[m\33[Ktk/history/\33[01;31m\33[Kclam\33[m\33[Kscan.log
 2>&1 ; if [ `fuser 
.\33[01;31m\33[Kclam\33[m\33[Ktk/history/\33[01;31m\33[Kclam\33[m\33[Kscan.log 
2>/dev/null` = \"\" ]; then  echo Still running 
>>.\33[01;31m\33[Kclam\33[m\33[Ktk/history/\33[01;31m\33[Kclam\33[m\33[Kscan.log
 ; else  /usr/local/bin/\33[01;31m\33[Kclam\33[m\33[Kdscan --quiet --multiscan 
--fdpass --log=\"$HOME/.\33[01;31m\33[Kclam\33[m\33[Ktk/history/$(/bin/date 
+\\%b-\\%d-\\%Y).log\" / 
>>.\33[01;31m\33[Kclam\33[m\33[Ktk/history/\33[01;31m\33[Kclam\33[m\33[Kscan.log
 2>&1 ; fi # fresh\33[01;31m\33[Kclam\33[m\33[K update and 
\33[01;31m\33[Kclam\33[m\33[K-scan\n", 965) = 965
========================dgp@dgp-p6803w:~$ stty -aspeed 38400 baud; rows 25; 
columns 80; line = 0;intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol 
= <undef>;eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; 
rprnt = ^R;werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;-parenb 
-parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts-ignbrk -brkint 
-ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff-iuclc -ixany 
-imaxbel iutf8opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 
tab0 bs0 vt0 ff0isig icanon iexten echo echoe echok -echonl -noflsh -xcase 
-tostop -echoprtechoctl echoke -flusho -extprocdgp@dgp-p6803w:~$ echo 
$TERMxtermdgp@dgp-p6803w:~$ pse xtermUID          PID    PPID  C STIME TTY      
    TIME CMDdgp         3841    1862  0 12:38 ?        00:00:03 xterm -T x3831 
-n x3831 -geometry 80x25 -fn 12x24 -sb -vb -cn -sl 9999 -lsdgp         3877    
1862  0 12:38 ?        00:00:01 xterm -T x3867 -n x3867 -geometry 80x25 -fn 
12x24 -sb -vb -cn -sl 9999 -lsdgp         3913    1862  0 12:38 ?        
00:00:01 xterm -T x3903 -n x3903 -geometry 80x25 -fn 12x24 -sb -vb -cn -sl 9999 
-lsdgp         3949    1862  0 12:38 ?        00:00:01 xterm -T x3939 -n x3939 
-geometry 80x25 -fn 12x24 -sb -vb -cn -sl 9999 -lsdgp@dgp-p6803w:~$ 
-----Original Message-----
From: Paul Eggert <eggert@cs.ucla.edu>
To: David G. Pickett <dgpickett@aol.com>
Cc: 56843@debbugs.gnu.org
Sent: Sat, Jul 30, 2022 2:17 pm
Subject: Re: bug#56843: grep mangling lines

I'm not seeing the problem on Ubuntu 22.04 LTS, using grep 3.7 and GNOME 
Terminal 3.44.0 using VTE 0.68.0 +BIDI +GNUTLS +ICU +SYSTEMD. The output 
isn't even colored unless I pass something like '--color=always' to 
'grep', which leads me to wonder whether you're using an alias for 
'grep' instead of the real thing.

Here's how I tried to reproduce the problem. What happens when you try 
the same thing on your platform? and what is your platform?

$ cat >x <<'EOF'
 > 30 23 * * * /usr/bin/freshclam --datadir=/home/dgp/.clamtk/db 
--log=/home/dgp/.clamtk/db/freshclam.$(/bin/date +\%b-\%d-\%Y).log 
 >/home/dgp/.clamtk/db/freshclam_cron.log 2>&1 ; 
/usr/local/bin/clamdscan --config-file=/etc/clamav/clamd.conf --reload 
--log="$HOME/.clamtk/history/$(/bin/date +\%b-\%d-\%Y).log" 
 >>.clamtk/history/clamscan.log 2>&1 ; /usr/local/bin/clamdscan 
--config-file=/etc/clamav/clamd.conf --quiet --multiscan --fdpass 
--log="$HOME/.clamtk/history/$(/bin/date +\%b-\%d-\%Y).log" $HOME 
 >>.clamtk/history/clamscan.log 2>&1 # freshclam update and clam-scan
 > EOF
$ cat x | grep clam | diff x -
$ e=$(printf '\033')
$ cat x | grep --color=always clam | sed "s/$e\\[[0-9;]*.//g" | diff x -
$ which grep
/usr/bin/grep