How to prevent grep command from throwing a system trap if No match is found.
Hi
How to prevent grep command from throwing a system trap(or returning error status) if No match is found in the specified file(s) ?
Consider this simple shell script:
Now if the files server* dont have matching string "ABC", it throws the trap and gets caught, which I dont want to happen.
I want the file logfile.log to be empty if no match is found.
But if, the file server* dont even exist, then I want trap to catch it and show the error.
find: /home/Upload/*: No such file or directory
I am getting a find error when I run
for FILE in `find /home/Upload/* -prune -type f -newer TIMEFILE`
do
I need to run this job every 10 minutes to upload any new files that were added. Is there an easy way to prevent this?
Thanks (6 Replies)
Hello,
How do I use grep to find a pattern in a list of file and then display 5 lines after the pattern is matched
Eg:
I want to match the string GetPresentCode in all files in a folder and then see 4 lines following this match. I am not sure if grep is what should be used to achieve. Thanks!... (3 Replies)
Hi
i have a file which have a pattern like this
Nov 10 session closed
Nov 10 Nov 9 08:14:27 EST5EDT 2010 on tty .
Nov 10 Oct 19 02:14:21 EST5EDT 2010 on pts/tk .
Nov 10 afrtetryytr
Nov 10 session closed
Nov 10 Nov 10 03:21:04 EST5EDT 2010
Dec 8 Nov 10 05:03:02 EST5EDT 2010
... (13 Replies)
Hi,
I am using following code to send an e-mail with attachment and body.
echo "To: user1@mail.com,user2@mail.com" > mail.tmp
echo "Cc: user3@mail.com,user4@mail.com" >> mail.tmp
echo "From: group@mail.com" >> mail.tmp
echo "Subject: my report" >> mail.tmp
echo "please see as attached"... (6 Replies)
Hi,
I need something unusual, I guess. I need to start a process, and if that process displays a specific error message, I need to kill that process and restart it.
Something like:
startprocess | grep -i "This is the specific error message" && kill $pidof(startprocess)
Explanation, I need... (4 Replies)
Hello, can someone help me how to find a word and 2 lines after it and then send the output to another file.
For example, here is myfile1.txt. I want to search for "Error" and 2 lines below it and send it to myfile2.txt
I tried with grep -A but it's not supported on my system.
I tried with awk,... (4 Replies)
I need to help to work this
Print everything between 2 patterns if grep is not found the search word
example
Detroit
orange
cat
bat
rat
apple
sed -n "/Detroit,/apple/p" d |grep chicago
output would be
Detroit
orange
cat
bat
rat (1 Reply)
Hello.
In bash, is there a way to trap error "file not found" when a script call another script which is not found; then abort.
Example ( part of script running with -x option set) :
+ return 0
+ RETURN_CODE=0
+ ]
+ /root/bin/200_yast_install/00_reset_yast_install
bash:... (5 Replies)
Hello,
one step in a shell script i am writing, involves Grep command to search a regular expression in a line an only print the string after the match
an example line is below
/logs/GRAS/LGT/applogs/lgt-2016-08-24/2016-08-24.8.log.zip:2016-08-24 19:12:48,602 ERROR... (9 Replies)
Discussion started by: Ramneekgupta91
9 Replies
LEARN ABOUT OSF1
trap
trap(1) User Commands trap(1)NAME
trap, onintr - shell built-in functions to respond to (hardware) signals
SYNOPSIS
sh
trap [ argument n [n2...]]
csh
onintr [-| label]
ksh
*trap [ arg sig [ sig2...]]
DESCRIPTION
sh
The trap command argument is to be read and executed when the shell receives numeric or symbolic signal(s) (n). (Note: argument is scanned
once when the trap is set and once when the trap is taken.) Trap commands are executed in order of signal number or corresponding symbolic
names. Any attempt to set a trap on a signal that was ignored on entry to the current shell is ineffective. An attempt to trap on signal 11
(memory fault) produces an error. If argument is absent all trap(s) n are reset to their original values. If argument is the null string
this signal is ignored by the shell and by the commands it invokes. If n is 0 the command argument is executed on exit from the shell. The
trap command with no arguments prints a list of commands associated with each signal number.
csh
onintr controls the action of the shell on interrupts. With no arguments, onintr restores the default action of the shell on interrupts.
(The shell terminates shell scripts and returns to the terminal command input level). With the - argument, the shell ignores all inter-
rupts. With a label argument, the shell executes a goto label when an interrupt is received or a child process terminates because it was
interrupted.
ksh
trap uses arg as a command to be read and executed when the shell receives signal(s) sig. (Note that arg is scanned once when the trap is
set and once when the trap is taken.) Each sig can be given as a number or as the name of the signal. trap commands are executed in order
of signal number. Any attempt to set a trap on a signal that was ignored on entry to the current shell is ineffective. If arg is omitted
or is -, then the trap(s) for each sig are reset to their original values. If arg is the null (the empty string, e.g., "" ) string then
this signal is ignored by the shell and by the commands it invokes. If sig is ERR then arg will be executed whenever a command has a non-
zero exit status. If sig is DEBUG then arg will be executed after each command. If sig is 0 or EXIT for a trap set outside any function
then the command arg is executed on exit from the shell. The trap command with no arguments prints a list of commands associated with each
signal number.
On this man page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation are not
performed.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), exit(1), ksh(1), sh(1), attributes(5)SunOS 5.10 23 Oct 1994 trap(1)