Sponsored Content
Top Forums Shell Programming and Scripting Maintain Scope of the variable in UNIX Post 302661477 by Ygor on Monday 25th of June 2012 09:45:46 AM
Old 06-25-2012
In bash, variables are local to pipes.

Replace
Code:
cat file | while read line
do
   :
done

With
Code:
while read line
do
   :
done < file

This User Gave Thanks to Ygor For This Post:
 

10 More Discussions You Might Find Interesting

1. Programming

C++ variable scope and mutexes

I've been wondering if I can make mutexes much easier to use in C++ with creative use of a locking class and variable scope, but I'm not sure if things happen in the order I want. Here's pseudocode for something that could use the class: int someclass::getvalue() { int retval; ... (0 Replies)
Discussion started by: Corona688
0 Replies

2. Shell Programming and Scripting

problem with shell variable's scope

Hi, I am stuck while developing a shell sub-routine which checks the log file for "success" or "failure". The subroutine reads the log file and checks for key word "success", if found it set the variable (found=1). It returns success or failure based on this variable. My problem is, I can... (2 Replies)
Discussion started by: cjjoy
2 Replies

3. Shell Programming and Scripting

How to maintain wildcard array variable

Hi all, I have this scenario where:- The file that I want to save its name into array df is my.08120323.trx which is located in the dir as below: $ pwd /u01/abc/def/SRC_datafiles $ ls *trx my.08120323.trx $ df=*"trx" ##keeping the filename my.08120323.trx into df $... (2 Replies)
Discussion started by: luna_soleil
2 Replies

4. Shell Programming and Scripting

scope of the variable - Naga

Hi All, I am new to unix shell scripting, in the below script "num" is an input file which contains a series of numbers example : 2 3 5 8 I want to add the above all numbers and want the result finally outside the while loop. it prints the value zero instead of the actual expected... (13 Replies)
Discussion started by: nagnatar
13 Replies

5. Shell Programming and Scripting

variable scope

Hi, I want to know about the variable scope in shell script. How can we use the script argument inside the function? fn () { echo $1 ## I want this argument should be the main script argument and not the funtion argument. } also are there any local,global types in shell script? if... (3 Replies)
Discussion started by: shellwell
3 Replies

6. UNIX for Dummies Questions & Answers

Bash loops and variable scope

Hi All, I've been researching this problem and I am pretty sure that the issue is related to the while loop and the piping. There are plenty of other threads about this issue that recommend removing the pipe and using redirection. However, I haven't been able to get it working using the ssh and... (1 Reply)
Discussion started by: 1skydive
1 Replies

7. Shell Programming and Scripting

Help with retaining variable scope

Hi, I use Korn Shell. Searched Forum and modified the way the file is input to the while loop, but still the variable does not seem to be retaining the final count. while read name do Tmp=`echo $name | awk '{print $9 }'` Count=`cat $Tmp | wc -l`... (6 Replies)
Discussion started by: justchill
6 Replies

8. Shell Programming and Scripting

Variable scope in bash

Hello! Before you "bash" me with - Not another post of this kind Please read on and you will understand my problem... I am using the below to extract a sum of the diskIO on a Solaris server. #!/bin/sh PATH=/usr/bin:/usr/sbin:/sbin; export PATH TEMP1="/tmp/raw-sar-output.txt$$"... (3 Replies)
Discussion started by: haaru
3 Replies

9. Shell Programming and Scripting

BASH: variable and function scope and subscripts

Hi, I'm a Delphi developer new to linux, new to this forums and new to BASH programming and got a new task in my work: maintaining an existing set of BASH scripts. First thing I want to do is making the code more reliable as in my opinion it's really bad written. So here's the quest: I'm... (6 Replies)
Discussion started by: rse
6 Replies

10. Programming

Variable Scope in Perl

I have to admit that i have not used Perl at all and this is a singular occasion where i have to patch an existing Perl script. I dearly hope i do not have to do it again for the next 15 years and therefore try to avoid having to learn the programming language in earnest. The OS is AIX 7.1, the... (2 Replies)
Discussion started by: bakunin
2 Replies
compact(1)						      General Commands Manual							compact(1)

Name
       compact, uncompact, ccat - compress and uncompress files, and cat them

Syntax
       compact [name...]
       uncompact [name...]
       ccat [file...]

Description
       The  command compresses the named files using an adaptive Huffman code.	If no file names are given, the standard input is compacted to the
       standard output.  The command operates as an on-line algorithm.	Each time a byte is read, it is encoded immediately according to the  cur-
       rent  prefix  code.   This code is an optimal Huffman code for the set of frequencies seen so far.  It is unnecessary to prepend a decoding
       tree to the compressed file since the encoder and the decoder start in the same state and stay synchronized.  Furthermore, and can  operate
       as filters.  In particular,
	    ... | compact | uncompact | ...
       operates as a (very slow) no-op.

       When  an  argument file is given, it is compacted and the resulting file is placed in file.C; file is unlinked.	The first two bytes of the
       compacted file code the fact that the file is compacted.  This code is used to prohibit recompaction.

       The amount of compression to be expected depends on the type of file being compressed.  Typical values of compression are: Text (38%), Pas-
       cal Source (43%), C Source (36%) and Binary (19%).  These values are the percentages of file bytes reduced.

       The command restores the original file from a file compressed by If no file names are given, the standard input is uncompacted to the stan-
       dard output.

       The command cats the original file from a file compressed by without uncompressing the file.

       The command is present only for compatibility.  In general, the command runs faster and gives better compression.

Restrictions
       The last segment of the file name must contain fewer than thirteen characters to allow space for the appended '.C'.

Files
       compacted file created by compact, removed by uncompact

See Also
       compress(1)

																	compact(1)
All times are GMT -4. The time now is 08:08 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy