Sponsored Content
Top Forums Shell Programming and Scripting Redirect output to memory instead of an external file Post 302923136 by shamrock on Thursday 30th of October 2014 04:07:47 PM
Old 10-30-2014
Quote:
Originally Posted by popeye
I use the following as an example. I find myself always doing this and I believe my scripts would run much faster if I put the sed results into a place in memory rather than writing to files. Again, its not about sed, its about redirecting to a place in memory rather than an external file.

Code:
#!/bin/bash
sed -r 's/\s+/ /g' vts.txt > vts2
while read x y z
do 
echo $y
done < vts2

Now the following obviously doesnt work, I provide it for illustration

Code:
#!/bin/bash
vts2=`sed -r 's/\s+/ /g' vts.txt`
while read x y z
do
 echo $y
done < $vts2

That's exactly the reason why pipes were invented...
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

redirect output to file?

Hi: I am currently working on a program which requires direct its ouput to a file here is an example ./proram arg_1 arg_2 when program ends all output will be arg_2 file Is that possible I am not a bad programmer, However I am stuck there. Can anyone give a hint? Thanks SW (1 Reply)
Discussion started by: slackware
1 Replies

2. UNIX for Dummies Questions & Answers

Redirect output to a file

Ahhhrrrggg I'm having a brain fart... I want to take the output of a command and redirect it to a file... This works.... $ man cp | cat >> copy_help but this doesn't keytool -help |cat >> keytool_help It just produces... these lines... more keytool_help ] ... ... (11 Replies)
Discussion started by: jimmyc
11 Replies

3. UNIX for Dummies Questions & Answers

redirect output to a file name

Hi all!! is possible to assign the output of some command to filename, i.e. grep_output.txt Otherwise, I want to open a new file which name is inside another, how can I do it? Thanks a lot! (7 Replies)
Discussion started by: csecnarf
7 Replies

4. HP-UX

Can I copy a Unix file to a external memory stick?

I'm doing server maintainence to a HP UX server and I have 2 files that someone need for an unknown reason. I was wondering If I can put this files on a memory stick, or is there someother way I have to copy it for them? (3 Replies)
Discussion started by: MarcKim
3 Replies

5. Shell Programming and Scripting

How redirect standard output to a file

Hi guys, i have a script named purgeErrors.ksh, when i execute this script i need to redirect the output to a log file in the same directory, how can i do that ?? -- Aditya (5 Replies)
Discussion started by: chaditya
5 Replies

6. Shell Programming and Scripting

How to redirect output of ls to a file?

Hi All, I want to redirect only the file names to a new file from the ls -ltr directroy. how Can i do it. my ls -ltr output will be as below. -rwxr-xr-x 1 118 103 28295 Jul 26 2006 event.podl -rwxr-xr-x 1 118 103 28295 Jul 26 2006 xyz.podl I want my new file... (6 Replies)
Discussion started by: girish.raos
6 Replies

7. Shell Programming and Scripting

Redirect the output in a file and on screen

I am trying to get following result from the scipt I have. First time it generates the o/p in correct format. However if I run it again it appends to the existing file. I would like to see o/p on screen as well as save it in file. Everytime it should create new file. ## I/P file 0174 0175... (3 Replies)
Discussion started by: dynamax
3 Replies

8. Shell Programming and Scripting

script to mail monitoring output if required or redirect output to log file

Below script perfectly works, giving below mail output. BUT, I want to make the script mail only if there are any D-Defined/T-Transition/B-Broken State WPARs and also to copy the output generated during monitoring to a temporary log file, which gets cleaned up every week. Need suggestions. ... (4 Replies)
Discussion started by: aix_admin_007
4 Replies

9. Shell Programming and Scripting

Redirect script output to a file and mail the output

Hi Guys, I want to redirect the output of 3 scripts to a file and then mail the output of those three scripts. I used below but it is not working: OFILE=/home/home1/report1 echo "report1 details" > $OFILE =/home/home1/1.sh > $OFILE echo... (7 Replies)
Discussion started by: Vivekit82
7 Replies

10. Shell Programming and Scripting

Unable to redirect output to a file

I m not able to redirect the java version to a file however, it shows as output when I run my script. bash-3.2$ more 1test.tmp java_version=`which java` echo "MY JAVA:"$java_version version=`"$java_version" -version` echo $version >>/tmp/moht/java_version.log $java_version -version 2... (4 Replies)
Discussion started by: mohtashims
4 Replies
SHELL-QUOTE(1)						User Contributed Perl Documentation					    SHELL-QUOTE(1)

NAME
shell-quote - quote arguments for safe use, unmodified in a shell command SYNOPSIS
shell-quote [switch]... arg... DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands or files with embedded white space or shell globbing characters safely. Here are a few examples. EXAMPLES
ssh preserving args When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and passes them to "$SHELL -c". This doesn't work as intended: ssh host touch 'hi there' # fails It creates 2 files, hi and there. Instead, do this: cmd=`shell-quote touch 'hi there'` ssh host "$cmd" This gives you just 1 file, hi there. process find output It's not ordinarily possible to process an arbitrary list of files output by find with a shell script. Anything you put in $IFS to split up the output could legitimately be in a file's name. Here's how you can do it using shell-quote: eval set -- `find -type f -print0 | xargs -0 shell-quote --` debug shell scripts shell-quote is better than echo for debugging shell scripts. debug() { [ -z "$debug" ] || shell-quote "debug:" "$@" } With echo you can't tell the difference between "debug 'foo bar'" and "debug foo bar", but with shell-quote you can. save a command for later shell-quote can be used to build up a shell command to run later. Say you want the user to be able to give you switches for a command you're going to run. If you don't want the switches to be re-evaluated by the shell (which is usually a good idea, else there are things the user can't pass through), you can do something like this: user_switches= while [ $# != 0 ] do case x$1 in x--pass-through) [ $# -gt 1 ] || die "need an argument for $1" user_switches="$user_switches "`shell-quote -- "$2"` shift;; # process other switches esac shift done # later eval "shell-quote some-command $user_switches my args" OPTIONS
--debug Turn debugging on. --help Show the usage message and die. --version Show the version number and exit. AVAILABILITY
The code is licensed under the GNU GPL. Check http://www.argon.org/~roderick/ or CPAN for updated versions. AUTHOR
Roderick Schertler <roderick@argon.org> perl v5.16.3 2010-06-11 SHELL-QUOTE(1)
All times are GMT -4. The time now is 04:07 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy