Re: bizarre trap behavior while reading a file

2011-03-29 Thread tytus64
Chet Ramey wrote: > > You might have better luck moving the trap command inside the { ... }, > before the while loop. > Yes. I realized that after a bit of testing :). Thanks -- View this message in context: http://old.nabble.com/bizarre-trap-behavior-while-re

Re: bizarre trap behavior while reading a file

2011-03-29 Thread Greg Wooledge
On Tue, Mar 29, 2011 at 08:02:17AM -0400, Steven W. Orr wrote: > Is there a difference between > > while read line < file > do > stuff > done > > vs > > while read line > do > stuff > done < file Yes. It's a huge difference. In the first one, the file is re-opened by read every time t

Re: bizarre trap behavior while reading a file

2011-03-29 Thread Steven W. Orr
On 3/29/2011 2:33 AM, Mart Frauenlob wrote: On 28.03.2011 18:03, tytus64 wrote: [...] trap "" HUP; cat $log_file | { while read line [...] useless use of cat! while read ... < file no need for a subshell actually (introducted by the pipe). I'm a big opponent of useless cats, but I ha

Re: bizarre trap behavior while reading a file

2011-03-28 Thread Mart Frauenlob
On 28.03.2011 18:03, tytus64 wrote: [...] trap "" HUP; cat $log_file | { while read line [...] useless use of cat! while read ... < file no need for a subshell actually (introducted by the pipe).

Re: bizarre trap behavior while reading a file

2011-03-28 Thread Chet Ramey
On 3/28/11 12:03 PM, tytus64 wrote: > OK. Thanks everybody for their input. Really appreciate all the answers. I > modified the first loop as follows to get the subshell to ignore HUP signal: > > > trap "" HUP; cat $log_file | { > while read line > do > line_num=`expr $line_num + 1

Re: bizarre trap behavior while reading a file

2011-03-28 Thread tytus64
$log_file | { while read line do line_num=`expr $line_num + 1` echo $line_num: $line >> ./out.log done } -- View this message in context: http://old.nabble.com/bizarre-trap-behavior-while-reading-a-file-tp31242064p31259743.html Sent from the Gnu - Bash mailing list archive at Nabble.com.

Re: bizarre trap behavior while reading a file

2011-03-28 Thread Chet Ramey
On 3/28/11 11:39 AM, tytus64 wrote: >> There is a bash process that is forked to execute the `while read ...' >> in the first pipeline loop. It has to hang around the whole time, so it >> can run the while loop and exit with the correct status. If you send it >> a SIGHUP with `killall bash', it

Re: bizarre trap behavior while reading a file

2011-03-28 Thread tytus64
bash', it will exit. > Thanks for all the answers. I think I understand the problem now. I wonder though if there is any way to disable default HUP handling int the subprocess executing the loop? -- View this message in context: http://old.nabble.com/bizarre-trap-behavior-while-reading-a-file-t

Re: bizarre trap behavior while reading a file

2011-03-28 Thread Chet Ramey
On 3/28/11 9:59 AM, tytus64 wrote: > > Interesting... > I used kill -HUP instead of killall -HUP and it works > without interrupting the first loop. I also noticed 2 processes running when > the first loop is iterating but only 1 when the second loop is iterating: There is a bash process that

Re: bizarre trap behavior while reading a file

2011-03-28 Thread Greg Wooledge
On Mon, Mar 28, 2011 at 06:59:23AM -0700, tytus64 wrote: > > Interesting... > I used kill -HUP instead of killall -HUP and it works > without interrupting the first loop. I also noticed 2 processes running when > the first loop is iterating but only 1 when the second loop is iterating: > > $ p

Re: bizarre trap behavior while reading a file

2011-03-28 Thread tytus64
I probably receives SIGHUP but I am not sure about the rules of process naming: why instead of cat? -- View this message in context: http://old.nabble.com/bizarre-trap-behavior-while-reading-a-file-tp31242064p31258525.html Sent from the Gnu - Bash mailing list archive at Nabble.com.

Re: bizarre trap behavior while reading a file

2011-03-28 Thread Chet Ramey
On 3/28/11 9:12 AM, tytus64 wrote: > > > Chet Ramey wrote: >> >> On 3/25/11 5:25 PM, tytus64 wrote: >> >> You don't say anything about what version of bash you're using or what OS >> you're on, but I couldn't reproduce it. >> >> >> > > I am running Fedora release 13 (Goddard) with GNU bash, vers

Re: bizarre trap behavior while reading a file

2011-03-28 Thread tytus64
on 4.1.7(1)-release (x86_64-redhat-linux-gnu). It is even more bizarre that you could not reproduce it. I can reproduce it at will... -- View this message in context: http://old.nabble.com/bizarre-trap-behavior-while-reading-a-file-tp31242064p31257975.html Sent from the Gnu - Bash mailing list archive at Nabble.com.

Re: bizarre trap behavior while reading a file

2011-03-28 Thread Greg Wooledge
On Fri, Mar 25, 2011 at 02:25:35PM -0700, tytus64 wrote: > while read line > do > line_num=`expr $line_num + 1` > echo $line_num: $line >> ./out.log > done < $log_file Although it's not directly related to your question, I feel obliged to point out that you can increment a variable without

Re: bizarre trap behavior while reading a file

2011-03-25 Thread Chet Ramey
On 3/25/11 5:25 PM, tytus64 wrote: > > I started execution of the following script and and repeatedly sent a SIGHUP > to it from another shell. If SIGHUP is received within the first while loop > the loop terminates with "wc -l" printing fewer than 4158 lines. If SIGHUP > is received within the se

bizarre trap behavior while reading a file

2011-03-25 Thread tytus64
t; $log_file wc -l out.log exit 0 -- View this message in context: http://old.nabble.com/bizarre-trap-behavior-while-reading-a-file-tp31242064p31242064.html Sent from the Gnu - Bash mailing list archive at Nabble.com.