Executing many commands at once


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Executing many commands at once
# 1  
Old 11-19-2009
Executing many commands at once

Hi,

I want to run these two commands one after the other.

Code:
awk 'BEGIN {OFS="\t"} {print $2}'
sort -u

rather than typing awk 'BEGIN {OFS="\t"} {print $2}' file1 > file2, then sort -u file2 > file3. Is it possible to run both commands on file1 then get output file3?

Its kinda hard for me to explain but i hope its clear

Kyle
# 2  
Old 11-19-2009
Does this work for you?
Code:
awk 'BEGIN {OFS="\t"} {print $2}' file1 | sort -u > file3

# 3  
Old 11-19-2009
hey thanks

what if I wanted to do like 10 commands at once?? should i just have | in between each command?

Kyle

so lets say I wanted to do 3 commands at once... this would work?

Code:
awk 'BEGIN {OFS="\t"} {print $1, $2}' file.txt | awk 'BEGIN {OFS="\t"} {print $1}' | sort -u > file2.txt


Last edited by kylle345; 11-19-2009 at 01:59 PM..
# 4  
Old 11-19-2009
The best way to learn it is to try it out! Smilie
# 5  
Old 11-19-2009
Quote:
Originally Posted by kylle345
hey thanks

what if I wanted to do like 10 commands at once?? should i just have | in between each command?
The pipe "|" only works when one command sends it output to standard out and the next command in the pipeline accepts input to standard in.

You might benefit from a review of this Wikipedia page:

Pipeline (Unix) - Wikipedia, the free encyclopedia
# 6  
Old 11-19-2009
If the commands aren't operating on output of previous commans, you can just put them all in a file and (after giving it execute perms - often "chmod 755 file") run that file instead:

Code:
$ cat > mycommands
command1
command2
command3
... 
command259
(CTRL-D)
$ chmod 755 mycommands
$ ./mycommands

If the next command shouldn't be run if the previous command fails, use:

Code:
$ cd /foo && cat abc
# only does the "cat" if you can chdir to /foo

or, if you should only run it on failure:

Code:
$ cd /foo || echo "Can't find /foo!"

Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Executing MQ commands in Perl

If you want to capture the output of any command, we then will be writing the system command in `` or qx. `` an qx works fine with all linux and windows system commands. But when I execute the below code.. it is displaying the output on the screen directly instead of storing to variable ... (3 Replies)
Discussion started by: giridhar276
3 Replies

2. Shell Programming and Scripting

Executing commands sequentially

Hello. I am new in shell script. Could anyone help me? I have un shell script. I need each command in it be sequentielly, when the first command ends the second starts. When the second ends et third starts, and so on Thanks in adavance (1 Reply)
Discussion started by: nurinolo
1 Replies

3. Shell Programming and Scripting

Executing two commands in parallel

Hi, I am stuck into a situation where i want to execute a command in my shell script well along with a previous command in order to achieve something but i am not figuring out a way. here is a snippet: service management restart rm -rf lock.file in the above, if you see, i am trying to... (5 Replies)
Discussion started by: sunrexstar
5 Replies

4. Shell Programming and Scripting

Executing commands

I need to execute a command to run my script several times with varying parameters perl ex.pl -b 130198 -e 130884 -c plot plot.txt 1_plot.txt perl ex.pl -b 1345 -e 1308 -c plot plot.txt 2_plot.txt perl ex.pl -b 1345567 -e 130898 -c plot plot.txt 3_plot.txt . . . 100's of excutions ... (2 Replies)
Discussion started by: Lucky Ali
2 Replies

5. Shell Programming and Scripting

Executing commands in different server

Hi Friends, I have a situation here, where I have a script running in one server, namely "SERVER1". Within this script which runs in SERVER1, I have a set of commands which has to connect to a different server (namely "SERVER2") and execute the commands accordingly. I have no experience at all... (1 Reply)
Discussion started by: sravicha
1 Replies

6. Red Hat

How commands are executing ?

Hi Folks, I have a small doubt, the binary commands under /bin and /sbin as well as other path binary files, if you peek deep into that, you can find the difference in the way of normal perl programming and some commands will be like binary files. how are the commands executing like the... (3 Replies)
Discussion started by: gsiva
3 Replies

7. UNIX for Dummies Questions & Answers

Executing commands after I log off

Hi, guys ! I have at home a simple network. I have a server that shares the internet connection to my computer and another another computer which is located in another room. When I want to download something, I'd like to download directly on the server, without letting my computer on. The server... (2 Replies)
Discussion started by: Sergiu-IT
2 Replies

8. Shell Programming and Scripting

Executing mpirun commands

Basically, I would like to run an mpirun query on my web server to query your databases via yours when using the BLAST program, however the server seems not able to execute even basic mpirun programs such as cpi (to calculate pi). Are there any settings I should take note of? I am running Perl... (0 Replies)
Discussion started by: tesswulf
0 Replies

9. UNIX for Dummies Questions & Answers

FTP - Executing Commands

I have written a script to ftp a file from Unix to an NT machine to authenticate ftp login I have added the information into the .netrc file when logged in using ftp the commands are not executed. Does anybody know how to make the command execute once username and password have been provided using... (2 Replies)
Discussion started by: hesmas
2 Replies

10. UNIX for Dummies Questions & Answers

Executing commands with xargs

I have a SQL script that requires values from the environment in order to execute. I found a way to get the desired results but my process is a little choppy. Any suggestions on how to clean this up would be greatly appreciated. SQL Script ------------- select a, b, c from d where a =... (1 Reply)
Discussion started by: bmopal
1 Replies
Login or Register to Ask a Question