Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: string comparison operators, what are they??
Top Forums Shell Programming and Scripting string comparison operators, what are they?? Post 98916 by vino on Monday 13th of February 2006 03:01:52 AM
Old 02-13-2006
Code:
set VAR1="hi"
set VAR2="bye"

if [ $VAR1 \< $VAR2 ] ; then
echo "$VAR1 is lexically less than $VAR2"
else
echo "$VAR1 is lexically greater than $VAR2"
fi
exit 0

In sh/ksh, you dont need to escape the < or >. They are recognized operators. So the hi-lited line would become if [ $VAR1 < $VAR2 ] ; then

Now in the unix world, < or > stands for redirecting input, output respectively. Since you need the literal meaning of "lesser than", you should use the following construct. Again the hi-lited line would become

if [[ $VAR1 < $VAR2 ]] ; then

Notice the extra [].

From man ksh

Code:
       [[ expression ]]
              Similar to the test and [ ... ] commands (described later), with
              the following exceptions:
                ·    There  are two additional binary operators: < and > which
                     return true if their first string operand is  less  than,
                     or  greater  than,  their  second string operand, respec-
                     tively.

 

10 More Discussions You Might Find Interesting

1. Programming

String Comparison

Hi all, I have a file like this ibhib=ere wefwfl=werfe sfdes=wef From this file, i need to get the lefthand side string with respect to the corresponding righthand side string. i.e, I need to get the string "ere" with respect to "ibhib". But i am stuck with how to compare a string... (1 Reply)
Discussion started by: abey
1 Replies

2. Shell Programming and Scripting

Get Comparison operators from with RexExp

Hello all im trying to get the Comparison operators from string with out much success I have : $myvar = "if (hhhh <= blah.count )" ; when I do : if ($myvar =~ m/.*().*/){ ....... } I keep getting the "=" and not "<=" why ? (3 Replies)
Discussion started by: umen
3 Replies

3. Shell Programming and Scripting

string comparison

The script will read a bunch of names, and test if it contains "John", but as below apparently ~ does not work, so what is the easiest way to perform string comparison in bash shell script? thanks ... elif then echo "get John" .... (2 Replies)
Discussion started by: fedora
2 Replies

4. UNIX for Dummies Questions & Answers

string comparison

Hi Guys i need to write a script to check the file structure I have added the the file headers in the configuration file and execute the file at the start of the script. Now the function checkFileStructure() { echo "Inside the function" filetocheck=$1 fileheader=$2 if ] then... (1 Reply)
Discussion started by: Swapna173
1 Replies

5. UNIX for Dummies Questions & Answers

Comparison operators: shortcut name

There are a number of comparison operators used in scripting and programming languages, such as the following: =, ==, ===, !=, =~, <, >, <=, >=, etc Is there a shortcut name for them, such as one has for as being any capital letter? If not, it would mean that I would have to list them all for a... (2 Replies)
Discussion started by: figaro
2 Replies

6. Shell Programming and Scripting

BASH - set specific user variable via string operators

Apologies for the utter triviality of this question, but we all have to start somewhere! I've also tried searching but this question is pretty vague so I didn't (a) really know what to search for or (b) get many relevant hits to what I did search for. Anyway, I'm in the process of self-teaching... (1 Reply)
Discussion started by: u5j84
1 Replies

7. Shell Programming and Scripting

to extract string from main string and string comparison

continuing from my previous post, whose link is given below as a reference https://www.unix.com/shell-programming-scripting/171076-shell-scripting.html#post302573569 consider there is create table commands in a file for eg: CREATE TABLE `Blahblahblah` ( `id` int(11) NOT NULL... (2 Replies)
Discussion started by: vivek d r
2 Replies

8. Homework & Coursework Questions

passing letters from an array into a string for string comparison

attempting the hangman program. This was an optional assignment from the professor. I have completed the logical coding, debugging now. ##I have an array $wordString that initializes to a string of dashes ##reflecting the number of letters in $theWord ##every time the user enters a (valid)... (5 Replies)
Discussion started by: lotsofideas
5 Replies

9. Shell Programming and Scripting

String comparison

hi team, i want to compare the below string from logs, but its is not working. if ]; then echo "restart some process" fi (4 Replies)
Discussion started by: mfaizan40
4 Replies

10. Shell Programming and Scripting

awk string comparison unterminated quoted string andrule of thumb

I have the logic below to look up for matches within the columns between the two files with awk. In the if statement is where the string comparison is attempted with == The issue seems to be with the operands, as 1. when " '${SECTOR}' " -- double quote followed by single quote -- awk matches... (1 Reply)
Discussion started by: deadyetagain
1 Replies

LEARN ABOUT OSX

platform::shell

platform::shell(n)					       Tcl Bundled Packages						platform::shell(n)

__________________________________________________________________________________________________________________________________________________

NAME

       platform::shell - System identification support code and utilities

SYNOPSIS

       package require platform::shell ?1.1.4?

       platform::shell::generic shell
       platform::shell::identify shell
       platform::shell::platform shell
_________________________________________________________________

DESCRIPTION

       The platform::shell package provides several utility commands useful for the identification of the architecture of a specific Tcl shell.

       This  package  allows the identification of the architecture of a specific Tcl shell different from the shell running the package. The only
       requirement is that the other shell (identified by its path), is actually executable on the current machine.

       While for most platform this means that the architecture of the interrogated shell is identical to the architecture of  the  running  shell
       this  is  not generally true. A counter example are all platforms which have 32 and 64 bit variants and where a 64bit system is able to run
       32bit code. For these running and interrogated shell may have different 32/64 bit settings and thus different identifiers.

       For applications like a code repository it is important to identify the architecture of the shell which will  actually  run  the  installed
       packages, versus the architecture of the shell running the repository software.

COMMANDS

       platform::shell::identify shell
	      This command does the same identification as platform::identify, for the specified Tcl shell, in contrast to the running shell.

       platform::shell::generic shell
	      This command does the same identification as platform::generic, for the specified Tcl shell, in contrast to the running shell.

       platform::shell::platform shell
	      This command returns the contents of tcl_platform(platform) for the specified Tcl shell.

KEYWORDS

       operating system, cpu architecture, platform, architecture

platform::shell 						       1.1.4							platform::shell(n)
All times are GMT -4. The time now is 02:10 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy