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
