Visit Our UNIX and Linux User Community

Command output to a variable.

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Command output to a variable.
# 1  
Old 12-14-2004
Question Command output to a variable.

With cut -c 8-13 myfile,

I am getting some numeric value.
In my shell script I am trying to assign something like this,
var=cut -c 8-13 myfile
But at the time of execution I am getting -c is not found.
If I dont assign, then script executes well.

Can we not simply use the value from one command output into the
variable in shell script?
# 2  
Old 12-14-2004
Instead of
var=cut -c 8-13 myfile
var=`cut -c 8-13 myfile`
# 3  
Old 12-14-2004
Meanwhile I started with awk. So on the similar lines I am trying to evaluate
awk o/p to var.

var=`awk <"$1""myfile" '{print substr($0,$start,$len)}'`
echo $var

After executing, I am getting awk error.

If at the place of $start & $len, I put 2 & 10 resp, it works.

Where am I making a mistake?
# 4  
Old 12-14-2004
What exactly is this line
var=`awk <"$1""myfile" '{print substr($0,$start,$len)}'`

supposed to be achieving?

Without knowing exactly what your problem is, something like
var=`awk -vs=$start -vl=$length '{print substr($0,s,l)}' filename`

may be more appropriate.

# 5  
Old 12-15-2004


that works. But let me explain what was my thought process behind prev command.

awk < filename - I understand as, file 'filename' is an input to awk. $1 param consists
dir loc where the file is residing.

In my fixed width file, I have these numeric values. Those I am retrieving with
# 6  
Old 12-15-2004
I know that that kind of redirection will work, but it's unneccessary - you can just take the filename onto the end of the command.

# 7  
Old 12-15-2004
Also I would like to get rid of leading zeros, after I read a number from fixed width
Say, 00000015 should be read as 15.

How would I achieve that?

Previous Thread | Next Thread
Test Your Knowledge in Computers #494
Difficulty: Easy
A block of code is a section of code that has been logically grouped together.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

How to get the output of a ISQL command in a variable?

I am trying to run a query which returns a sum value(a number). I want to get it in a variable so that i can refer to that variable in different places. when i am running the following command variable=`isql -Uuser -Sserver -Ppassword 1> select sum(count(*)) from where clm_id... (2 Replies)
Discussion started by: Sharma331
2 Replies

2. Shell Programming and Scripting

Output of find command to variable?

Hi, I'd like to assign the output of the find command to a variable. What I need is to run the find command, and if it returns zero files, the program exits. so i'm trying to assign the output of the find command to the $var1 variable....and then if this is less than one, I echo a... (2 Replies)
Discussion started by: horhif
2 Replies

3. UNIX for Advanced & Expert Users

ls output into a read command as a variable

I'm working on a short BASH script on my Ubuntu box that will run powerpoint scripts with MS Powerpoint Viewer 2007 via WINE. I can run the presentation when I run it manually but what i'd like to do is have the script look for the newest file then run it. #! /bin/sh # Start the newest... (2 Replies)
Discussion started by: binary-ninja
2 Replies

4. Shell Programming and Scripting

set variable to command output

I'm hoping you guys can help me out here. I've been trying different methods to try and get what IW as hoping would be a fairly simple script but has turned into a pain. Bit of background - I am writing a script to check values in certain failes to ensure they are corerct. I'm runnign this on... (2 Replies)
Discussion started by: stuc
2 Replies

5. Programming

Command output into a variable

Hi, with this command: cu -l /dev/ttyACM0 -s 9600 > name.txt I put the output of the port in a txt Is posible to do the same (or similar) in a var directly, inside a C program? cu -l /dev/ttyACM0 -s 9600 > variable ? I have trying this withs pipes, but i dont know how to... (6 Replies)
Discussion started by: daaran
6 Replies

6. UNIX for Dummies Questions & Answers

saving command output to a variable

Hello, I have a shell script containing a command string in the following format: command1 | command2 | cut -c9-16 The output from this is a record number (using characters 9-16 of the original output string) e.g. ORD-1234 I wish to save this value to a variable for use in later commands... (4 Replies)
Discussion started by: philjo
4 Replies

7. Shell Programming and Scripting

Assigning output of a command to variable

When I run time -p <command>, it outputs: real X.XX user X.XX sys X.XXwhere X.XX is seconds. How I can take just that first number output, the seconds of real time, and assign that to a variable? (9 Replies)
Discussion started by: jeriryan87
9 Replies

8. Shell Programming and Scripting

get characters from output of a command in a variable

Hi, i have two questions, I am new to programming 1. I have an output of a command and i want to get some specific part of it in a variable. i am trying sr=`some comand xyz| grep 'Last Changed Rev:' | cut -c19-` now variable sr gets a end of line character at end. output of the command... (3 Replies)
Discussion started by: muaz
3 Replies

9. UNIX for Dummies Questions & Answers

ls command output to variable in script

Hi, I wrote a script to get the oldest file from a directory path (which is passed as a parameter to the script) ######################################################### XMLFILE_PATH={$1} cd $XMLFILE_PATH JPM_FILENAME = `(ls -tr User* | head -1)` #echo $JPM_FILENAME ###### END... (1 Reply)
Discussion started by: dsrookie
1 Replies

10. Shell Programming and Scripting

Assigning output of command to a variable

Hi, I'm trying to assign the output of a command to a variable and then concat it with another string, however, it keeps overwriting the original string instead of adding on to the end of the string. Contents of test.txt --> This is a test var1="`head -n 1 test.txt`" echo $var1 (This is a... (5 Replies)
Discussion started by: oma04
5 Replies

Featured Tech Videos