Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

var substitution in a reg expr ?

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting var substitution in a reg expr ?
# 1  
Old 08-10-2005
var substitution in a reg expr ?
In a shell script, how I can achieve substitution of shell script var to a regular
expression, as shown below.


var=`head -1 file1`
awk '$0!~/$var/ {print $0}' file1 > file2


In the case above $var value literally considered for non-exists criteria.
# 2  
Old 08-10-2005
You have to double-quote $var for it to be expanded.

var=`head -1 file1`
awk '$0!~/"$var"/ {print $0}' file1 > file2


vino
# 3  
Old 08-10-2005
Quote:
Originally Posted by videsh77
In a shell script, how I can achieve substitution of shell script var to a regular
expression, as shown below.


var=`head -1 file1`
awk '$0!~/$var/ {print $0}' file1 > file2


In the case above $var value literally considered for non-exists criteria.
Code:
awk "!/$var/" file1 > file2

# 4  
Old 08-10-2005
Thanks futurelet, soln you provided works.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Programming

How to prevent incorrect string using reg expr in Java?

Hi All, I need your input on how to mask out / ignore a string that does not match a working regular expression (continually refining) pattern in Java. Below is the code snippet which is picking up all the lines with the correct regular expression string except one known so far: public... (0 Replies)
Discussion started by: gjackson123
0 Replies

2. Shell Programming and Scripting

test expr VS [ expr ]

What is the difference between test expr VS . For example : if test 5 -eq 6 echo "Wrong" and if echo "Wrong" bot will give the same output as Wrong. Now, what is the difference between these two? though they are producing the same result why we need two? Any answer will be... (2 Replies)
Discussion started by: ashok.g
2 Replies

3. Shell Programming and Scripting

perl: reg.expr: combine starting and ending removal in one exprecion

Hello, I am new in perl and in regular exprecion; so I am looking for help (or an experienced advise.) The target is a triming spaces from a string: i.e., remove spases from begining and from end of a string. One of main point of a searched solution is performance: for current task it is... (2 Replies)
Discussion started by: alex_5161
2 Replies

4. Solaris

diff b/w /var/log/syslog and /var/adm/messages

hi sirs can u tell the difference between /var/log/syslogs and /var/adm/messages in my working place i am having two servers. in one servers messages file is empty and syslog file is going on increasing.. and in another servers message file is going on increasing but syslog file is... (2 Replies)
Discussion started by: tv.praveenkumar
2 Replies

5. Shell Programming and Scripting

HowTo: reg expr doing grep "timestamp>$DesiredTime" logfile ?

I know I asked a similar question but I want to know if there is a regular expression existing that with a korn shell cmd, finds any timestamp data records in a file where it is greater then a timestamp in a shell variable ? something like : grep all records where it has a timestamp >... (5 Replies)
Discussion started by: Browser_ice
5 Replies

6. Shell Programming and Scripting

print column that match reg expr

Hi all, I want to cut a column which match the regular expression "beta", if I don't know the column number? cat test alpha;beta;gamma 11;22;33 44;55;66 77;88;99 should be command .... beta 22 55 (6 Replies)
Discussion started by: research3
6 Replies

7. Shell Programming and Scripting

PERL: Simple reg expr validate 6 digits number

Hi there! I'm trying to validate a simple 6 digits number with reg expr. I ONLY want 6 digits so when i type 7 digits the script should no validate the number. I've write this code: #!/usr/bin/perl while(<STDIN>){ if($_=~/\d{6}/){ print "Bingo!\n"; ... (2 Replies)
Discussion started by: BufferExploder
2 Replies

8. UNIX for Dummies Questions & Answers

scipt dividing strings /reg expr

Hello! I've got txt-file containing lots of data in sentences like this: ;;BA;00:00:03:00;COM;CLOQUET-LAFOLLYE;SIMON; but sometime more than on in a line like this: ;;BA;00:00:03:00;COM;CLOQUET-LAFOLLYE;SIMON;;;BA;00:00:03:00;REA;RTL9;;;;BAC;:00;TIT;SEMAINE SPECIALE ~SSLOGAN~T DVD;; ... (3 Replies)
Discussion started by: maco_home
3 Replies

9. Shell Programming and Scripting

Var substitution in awk - not working as expected

countA=`awk '/X/''{print substr($0,38,1)}' fName | wc -l` countB=`wc -l fName | awk '{print int($1)}'` echo > temp ratio=`awk -va=$countA -vc=$countB '{printf "%.4f", a/c}' temp` After running script for above I am getting an error as : awk: 0602-533 Cannot find or open file -vc=25. The... (3 Replies)
Discussion started by: videsh77
3 Replies

10. Shell Programming and Scripting

Text replace by position instead of reg expr.

Can we replace the contents the of the rows of file, from one position to another position by mentioning, some start position & the width? (4 Replies)
Discussion started by: videsh77
4 Replies
Login or Register to Ask a Question