I'm learning about the trap command from my bash book. I tried out the little script they gave:
But when I type control-c, the script just stops and the message is not displayed. I checked stty all and saw that control-c is intr, but the same thing happened whet I tried that. Can anyone tell me what I'm missing?
I'm using terminal (BSD) in OS X
Last edited by Scott; 04-07-2011 at 08:37 PM..
Reason: Code tags, please...
I'm using the trap command to capture any signals received whilst my script is running.
How's the best way of writing the signal and any other error messages to a file/error log' without having to type '2>$1' on the command line after the script name?
Cheers (3 Replies)
i have the following script that displays the current time until the user presses CTR + c.... but it does not work properly....
Something is not right with the trap command...
Help plz... :confused:
# script to continuously display current time.
# if script is terminated trap signal... (3 Replies)
Dear All
could you please explain me what does the trap command do and how I can write a program which can work as a trap command(in C Language). (1 Reply)
Could anybody tell me what the trap command does and how it performs the action it does. I had read the trap manual page but it is too concise that nothing is clear about it. Please tell how it works. (1 Reply)
Hi,
I would like to know the use of TRAP command. I am very new to the UNIX environment. I have just started learning the basic. So please teach me in a very simple way to understand.
Also i would like to know the use of following command:
trap 'dialog --msgbox "Script Aborted1" 6 50 ;... (2 Replies)
Hi folks,
I have tried to add some trap detection in the below script....this script is used to monitor database activities...in a rather awkward way :rolleyes:....
The idea behind adding trap is that....this script creates lots of temporary files in the running folder to store the count... (1 Reply)
Hello experts!
I need to know the use of trap command please
In one of our program we have trap "rm -f temp1 ; exit 1" 1 2 15 0
and program always exit with 1
there is a rm -f temp1 as well at the end of the program
as
rm -f temp1
exit 0
when I test a probram with set... (4 Replies)
dear all;
I can't under stand what does "trap" command do:
for example see below:
trap "echo; echo no interrupts >&2; sleep 3" 2 3 15
Plz , can any body explain the action of this command?
BR (3 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
That is the last reply I received from my instructor, and I'm looking for some alternatives.
When using... (2 Replies)
Hi Folks -
For some reason, my trap command is not working. It's placed just prior to a normal exit:
#:: ------------------------------------------------------------------------
#::-- Script Name: LCM_Backup.sh
#::
#::-- Description: This script leverages Utility.sh to perform LCM... (16 Replies)
Discussion started by: SIMMS7400
16 Replies
LEARN ABOUT X11R4
script
SCRIPT(1) User Commands SCRIPT(1)NAME
script - make typescript of terminal session
SYNOPSIS
script [options] [file]
DESCRIPTION
script makes a typescript of everything displayed on your terminal. It is useful for students who need a hardcopy record of an interactive
session as proof of an assignment, as the typescript file can be printed out later with lpr(1).
If the argument file is given, script saves the dialogue in this file. If no filename is given, the dialogue is saved in the file type-
script.
OPTIONS -a, --append
Append the output to file or to typescript, retaining the prior contents.
-c, --command command
Run the command rather than an interactive shell. This makes it easy for a script to capture the output of a program that behaves
differently when its stdout is not a tty.
-e, --return
Return the exit code of the child process. Uses the same format as bash termination on signal termination exit code is 128+n.
-f, --flush
Flush output after each write. This is nice for telecooperation: one person does `mkfifo foo; script -f foo', and another can
supervise real-time what is being done using `cat foo'.
--force
Allow the default output destination, i.e. the typescript file, to be a hard or symbolic link. The command will follow a symbolic
link.
-q, --quiet
Be quiet (do not write start and done messages to standard output).
-t[file], --timing[=file]
Output timing data to standard error, or to file when given. This data contains two fields, separated by a space. The first field
indicates how much time elapsed since the previous output. The second field indicates how many characters were output this time.
This information can be used to replay typescripts with realistic typing and output delays.
-V, --version
Display version information and exit.
-h, --help
Display help text and exit.
NOTES
The script ends when the forked shell exits (a control-D for the Bourne shell (sh(1)), and exit, logout or control-d (if ignoreeof is not
set) for the C-shell, csh(1)).
Certain interactive commands, such as vi(1), create garbage in the typescript file. script works best with commands that do not manipulate
the screen, the results are meant to emulate a hardcopy terminal.
It is not recommended to run script in non-interactive shells. The inner shell of script is always interactive, and this could lead to
unexpected results. If you use script in the shell initialization file, you have to avoid entering an infinite loop. You can use for
example the .profile file, which is read by login shells only:
if test -t 0 ; then
script
exit
fi
You should also avoid use of script in command pipes, as script can read more input than you would expect.
ENVIRONMENT
The following environment variable is utilized by script:
SHELL If the variable SHELL exists, the shell forked by script will be that shell. If SHELL is not set, the Bourne shell is assumed.
(Most shells set this variable automatically).
SEE ALSO csh(1) (for the history mechanism), scriptreplay(1)HISTORY
The script command appeared in 3.0BSD.
BUGS
script places everything in the log file, including linefeeds and backspaces. This is not what the naive user expects.
script is primarily designed for interactive terminal sessions. When stdin is not a terminal (for example: echo foo | script), then the
session can hang, because the interactive shell within the script session misses EOF and script has no clue when to close the session. See
the NOTES section for more information.
AVAILABILITY
The script command is part of the util-linux package and is available from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils
/util-linux/>.
util-linux June 2014 SCRIPT(1)