07-20-2006
Deleting all content in a file from command line
Hey guys,
I'd like to delete all text within a text file without actually deleting the file. Is there a vi command I can do from my prompt without actually going into the file and doing a %d i think it is... to remove all the text inside?
I want to add this to a cron job to erase all the data in a file at 12non and I can't find anything on how i'd do it the way i'd like
thanks!
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
hallo..i work in c-shell and i want to delete the content of a file without deleting the file itself...commands like
>filename or
echo -n > filename
didn't work....thanks in advance (2 Replies)
Discussion started by: tolkki
2 Replies
2. UNIX for Dummies Questions & Answers
Hi,
I want to delete a line in a file that contains a string. I tried:
grep -v "mystring" Myfile > Myfile
But this makes the Myfile empty. I read that I need to do something like:
grep -v "mystring" Myfile > Myfile.new
rm Myfile
mv Myfile.new Myfile
Is there a way to avoid creating a... (2 Replies)
Discussion started by: laiko
2 Replies
3. Shell Programming and Scripting
Hi
Is it possible to do the following in a single command
/usr/xpg4/bin/sed -e '/rows selected/d' /aemu/CALLAUTO/callauto.txt > /aemu/CALLAUTO/callautonew.txt
/usr/xpg4/bin/sed -e '/^$/d' /aemu/CALLAUTO/callautonew.txt > /aemu/CALLAUTO/callauto_new.txt
exit (1 Reply)
Discussion started by: aemunathan
1 Replies
4. UNIX for Dummies Questions & Answers
Hi All,
I have too many .gz files (test.gz).
Task is to remove first line of each file.
Can I do it without unzipping the files?
Your help is appreciated. (4 Replies)
Discussion started by: Chulamakuri
4 Replies
5. Shell Programming and Scripting
Hi all,
I have a huge file(size more that 5GB).
I want to do some manupulation with the records and write to another file.
As the size of the file is huge and there is a space constraint in that directory, I want to delete that record from first file after writing it in to second file.... (3 Replies)
Discussion started by: gani_85
3 Replies
6. UNIX for Dummies Questions & Answers
Hi
I have a file:
r58778.3|SOURCES={KEY=f665931a...,fw,221-705}|ERRORS={16_1:T,30_1:T,56_1:C,57_1:T,59_1:A,101_1:A,115:-,158_1:C,186_1:A,204:-,271_1:T,305:-,350_1:C,368_1:G,442_1:C,472_1:G,477_1:A}|SOURCE_1="Contig_1092402550638"(f665931a359e36cea0976db191ff60ff09cc816e)
I want to retain... (15 Replies)
Discussion started by: Alyaa
15 Replies
7. Shell Programming and Scripting
file 1
abcde,dfgdfg,sdfds
sdfsd,sdfd,sdfg,sdfs
dwfds,sdfgdfg,sdfsdf
file2
1
3
i need to delete the line numbers file 1 based on file2
i have taken in loop file 1 and
i cant able to delete that line number in file 1
Plz help (4 Replies)
Discussion started by: ragu.selvaraj
4 Replies
8. Shell Programming and Scripting
Hi all,
I ahve a program which has to delete a line in a file... if i run the sed command through shell prompt it works fine. But if run it using code its throwing error. May i know where i am doing wrong.
the file has 3 lines
# cat /root/.ssh/known_hosts... (4 Replies)
Discussion started by: vivek d r
4 Replies
9. UNIX for Beginners Questions & Answers
PGW|PGW_CDR_|2017-06-23 141946|2017-07-17 131633|2017-08-21
PGW|PGW_CDR_|2017-06-23 141946|2017-07-17 131633|2017-08-21
PGW|PGW_CDR_|2017-06-23 141946|2017-07-17 131633|2017-08-21
PGW|PGW_CDR_|2017-06-23 141946|2017-07-17 131633|2017-08-21
PGW|PGW_CDR_|2017-06-23 141946|2017-07-17... (6 Replies)
Discussion started by: swathi reddy1
6 Replies
10. Shell Programming and Scripting
Hi,
I have a shell script which has a for loop that scans list of files and do find and replace few variables using sed command. While doing this, it deletes the last line of all input file which is something wrong. how to fix this. please suggest. When i add an empty line in all my input file,... (5 Replies)
Discussion started by: rbalaj16
5 Replies
LEARN ABOUT X11R4
queuedefs
queuedefs(4) File Formats queuedefs(4)
NAME
queuedefs - queue description file for at, batch, and cron
SYNOPSIS
/etc/cron.d/queuedefs
DESCRIPTION
The queuedefs file describes the characteristics of the queues managed by cron(1M). Each non-comment line in this file describes one queue.
The format of the lines are as follows:
q.[njobj][nicen][nwaitw]
The fields in this line are:
q The name of the queue. a is the default queue for jobs started by at(1); b is the default queue for jobs started by batch (see
at(1)); c is the default queue for jobs run from a crontab(1) file.
njob The maximum number of jobs that can be run simultaneously in that queue; if more than njob jobs are ready to run, only the first
njob jobs will be run, and the others will be run as jobs that are currently running terminate. The default value is 100.
nice The nice(1) value to give to all jobs in that queue that are not run with a user ID of super-user. The default value is 2.
nwait The number of seconds to wait before rescheduling a job that was deferred because more than njob jobs were running in that job's
queue, or because the system-wide limit of jobs executing has been reached. The default value is 60.
Lines beginning with # are comments, and are ignored.
EXAMPLES
Example 1: A sample file.
#
#
a.4j1n
b.2j2n90w
This file specifies that the a queue, for at jobs, can have up to 4 jobs running simultaneously; those jobs will be run with a nice value
of 1. As no nwait value was given, if a job cannot be run because too many other jobs are running cron will wait 60 seconds before trying
again to run it.
The b queue, for batch(1) jobs, can have up to 2 jobs running simultaneously; those jobs will be run with a nice(1) value of 2. If a job
cannot be run because too many other jobs are running, cron(1M) will wait 90 seconds before trying again to run it. All other queues can
have up to 100 jobs running simultaneously; they will be run with a nice value of 2, and if a job cannot be run because too many other jobs
are running cron will wait 60 seconds before trying again to run it.
FILES
/etc/cron.d/queuedefs queue description file for at, batch, and cron.
SEE ALSO
at(1), crontab(1), nice(1), cron(1M)
SunOS 5.10 1 Mar 1994 queuedefs(4)