Assigning output of command to a variable

Login or Register to Ask a Question and Join Our Community

Assigning output of command to a variable

Tags

Top Forums Shell Programming and Scripting Assigning output of command to a variable

Prev Next

06-26-2006

Registered User

3, 0

Join Date: Jun 2006

Last Activity: 27 June 2006, 12:12 PM EDT

Posts: 3

Thanks Given: 0

Thanked 0 Times in 0 Posts

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 test)

var1=$var1"123"
echo $var1 (123s is a test [instead of: This is a test123)

The issue has something to do with the first line. If I simply assign a string like this:
var1="This is a test" , then it all works, but when I try to assign the output of a command to a variable, it does not add to the string properly.

Does anyone know how to get around this??

Thanks!!

oma04

View Public Profile for oma04

Find all posts by oma04

Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Expect - assigning UNIX command output to a variable

Hi, I'm writing a script that connects through ssh (using "expect") and then is supposed to find whether a process on that remote machine is running or not. Here's my code (user, host and password are obviously replaced with real values in actual script): #!/usr/bin/expect set timeout 1...

2. UNIX for Dummies Questions & Answers

Tcsh command for assigning output of awk to variable

Hi I have a text file with 2 values and I am trying to assign each value to a variable and then write those to text files. So if the textfile is data.txt with 2 values x and y I want to assign mean=x, and stdev=y and then write these out in text files alongwith the id ($id has already been...

3. Shell Programming and Scripting

Assigning bc output to a variable

I'm converting decimal to integer with bc, and I'd like to assign the integer output from bc to a variable 'val'. E.g. In the code below: If b is 5000.000, lines 6 and 8 will output: 5000 (5000.000+0.5)/1 | bc I'd like val to take the value 5000 though, rather than 5000.000 Does someone...

4. Shell Programming and Scripting

Assigning output from awk to variable

I have a script whose contents are as below result= awk 's=100 END {print s }' echo "The result is" $result The desired output is The result is 100 My script is running without exiting and i am also not getting the desired output. Please help

5. UNIX for Dummies Questions & Answers

Assigning the output of a command to a variable, where there may be >1 line returned?

Hello I am using unix CLI commands for the Synergy CM software. The command basically searches for a folder ID and returns the names of the projects the folder sits in. The result is assigned to a variable: FIND_USE=`ccm folder -fu -u -f "%name"-"%version" ${FOLDER_ID}` When the command...

6. Shell Programming and Scripting

Piping and assigning output to a variable in Perl

Hi All, I am trying to convert the below Csh code into Perl. But i have the following error. Can any expert help ? Error: ls: *tac: No such file or directory Csh set $ST_file = `ls -rt *$testid*st*|tail -1`; Perl my $ST_file = `ls -rt *$testid*st*|tail -1`;

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?

8. Shell Programming and Scripting

Assigning output to a variable

I am new to unix shell scripting. I was trying to convert each lines in a file to upper case. I know how to convert the whole file. But here i have to do line by line. I am getting it in the below mentioned script #!/bin/bash #converting lower to upper in a file #tr "" "" <file1...

9. Shell Programming and Scripting

Assigning output of command to a variable in shell

hi, I want to assign find command result into some temporary variable: jarPath= find /opt/lotus/notes/ -name $jarFile cho "the jar path $jarPath" where jarPath is temporary variable. Can anybody help on this. Thanks in advance ----Sankar

10. Shell Programming and Scripting

assigning command output to a shell variable

I have the sql file cde.sql with the below contents: abcdefghij abcwhendefothers sdfghj when no one else when others wwhen%others exception when others Now I want to search for the strings containing when others together and ceck whether that does not occur more than once in the...

Login or Register to Ask a Question

LEARN ABOUT SUNOS

onintr

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)