thank you ! As you write . It works . I thought it was captured by shell. In fact the error in cods. I am just a student . Someone told me some skills are import . However , I study it and find I can't use it right now . That lead careless . May be we need to find interest in programming . 2011/3/7 Cameron Simpson <cs@xxxxxxxxxx>: > On 07Mar2011 10:17, xinyou yan <yxy.716@xxxxxxxxx> wrote: > | I want to know when i use > | > | trap 'rm -f /tmp/my_tmp_file_$$' INT > | > | why shell itself capture the single and she shellscript exit. > > But it doesn't! > > The shell captures the signal, runs the rm command, and proceeds. > > | Here is the code from << Beginning Programming>> > | #!/bin/sh > | trap 'rm -f /tmp/my_tmp_file_$$' INT > | echo creating file /tmp/my_tmp_file_$$ > | date > /tmp/my_tmp_file_$$ > | > | echo "Press interrupt (Ctrl-C) to interrupt...." > | while [ -f /tmp/my_tmp_file_$$ ]; do > | echo File exists > | sleep 1 > | done > | echo The file no longer exists > > When I run this script, this all works just fine. > > | trap INT > > However, _this_ line above is incorrect. > "trap" requires a shell command to run, even if it is empty. > For example: > > trap 'echo INT received' INT > > >From "man sh": > > trap [-lp] [[arg] sigspec ...] > The command arg is to be read and executed when the shell > receives signal(s) sigspec. [...snip...] If arg is the null > string the signal specified by each sigspec is ignored by the shell > and by the commands it invokes. [...snip...] > > When I run the script it aborts at that line. > > Try changing that line to: > > trap 'echo INT received' INT > > and rerunning your script. > > Cheers, > -- > Cameron Simpson <cs@xxxxxxxxxx> DoD#743 > http://www.cskk.ezoshosting.com/cs/ > > More computing sins have been committed in the name of performance, > without necessariliy achieving it, than for all other reasons > combined. - Wulf > -- > users mailing list > users@xxxxxxxxxxxxxxxxxxxxxxx > To unsubscribe or change subscription options: > https://admin.fedoraproject.org/mailman/listinfo/users > Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines > -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
