01-21-2015
And the `cat file` stores the whole file in memory before the loop starts.
The while loop reads the file line by line, so only one line is in memory.
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hello there,
I wrote a shell script to modify the code for some of our clients in our client database. Before starting the data modification the program performs a few checks.
When a check is being performed, it should be shown on the screen of the user running the program, the result of... (5 Replies)
Discussion started by: JoBa
5 Replies
2. Shell Programming and Scripting
I have script like
echo -n FINISHED FEXP: ${TABLE2EXP}
echo $STATUS
I want the output of both the echo statement in one line
How can i do this (3 Replies)
Discussion started by: scorp_rahul23
3 Replies
3. Shell Programming and Scripting
Hello,
I'm writing some bash scripts and I'm trying to get an echo command and the output of another command to display on the same line. For example:
I want to run
echo "Operating System: " unameand have it displayed as
Operating System: Darwin
Thanks for your help! (7 Replies)
Discussion started by: codyhazelwood
7 Replies
4. Shell Programming and Scripting
Hi,
I try to write script and echo two command at the same line .
echo "A"
echo "B"
How can I pipe above two command at the same line in text file .
So, in the output text file , you can see below ???
A B
not
A
B
Any sugggestion ??? (4 Replies)
Discussion started by: chuikingman
4 Replies
5. Shell Programming and Scripting
I have a record.txt it will update weekly, and it could be 2 lines or more ...
it just echo each line to the script
san jose,23.34%
tampa,2.15%
dallas,30.20%
seattle,44.29%
Unknown,16.72%
How do i write a shell script to give me a test.pl or bash file which contain
#!/home/perl... (8 Replies)
Discussion started by: sabercats
8 Replies
6. Shell Programming and Scripting
Hi,
I have a problem with passing a echo output into a variable in bash
file='1990.tar'
NAME='echo $file | cut -d '.' -f1';
echo $NAME
the result is
echo $file | cut -d . -f1
however with this one,#!/bin/bash
file='1990.tar'
echo $file | cut -d '.' -f1
the result is what I... (2 Replies)
Discussion started by: 1988PF
2 Replies
7. Shell Programming and Scripting
Hi, I am trying to make a script to manage log. I want to write the name of the .gz I moved and the date :
for i in `ls $replog/*.gz`
do
echo " $i "
`echo $i date +%d:%m:%Y`
`echo $datee `>> $replog/mrnet.log
mv $i /var/log/vieux-logs
done
I need to echo... (10 Replies)
Discussion started by: Dabless
10 Replies
8. Shell Programming and Scripting
Hello,
I've been trying to find the answer to this with Google and trying to browse the forums, but I haven't been able to come up with anything. If this has already been answered, please link me to the thread as I can't find it.
I've been asked to write a script that pulls a list of our CPE... (51 Replies)
Discussion started by: rwalker
51 Replies
9. Shell Programming and Scripting
Currently using below script but echo it print the output in two line.
Input file all-vm-final-2.txt
CEALA08893 SDDC_SCUN DS_SIO_Workload_SAPUI_UAT_01 4
CEALA09546 SDDC_SCUN DS-SIO-PD5_Workload_UAT_SP1_Flash_07 4
CEALA09702 SDDC_SCUN DS-VSAN-RMP-WORKLOAD01 4
DEALA08762 SDDC_LDC... (3 Replies)
Discussion started by: ranjancom2000
3 Replies
10. UNIX for Beginners Questions & Answers
Hi, All:
I have one for ... loop code to generate a list of rename statement. However, echo the loop output on screen is OK. But store the echo output into a file is not working. So come here to seek help. My basic code is:
! /bin/ksh
echo > DAS_VetFed.txt
dir=/mydirectory
cd $dir
files=`ls... (6 Replies)
Discussion started by: duke0001
6 Replies
while(n) Tcl Built-In Commands while(n)
__________________________________________________________________________________________________________________________________________________
NAME
while - Execute script repeatedly as long as a condition is met
SYNOPSIS
while test body
_________________________________________________________________
DESCRIPTION
The while command evaluates test as an expression (in the same way that expr evaluates its argument). The value of the expression must a
proper boolean value; if it is a true value then body is executed by passing it to the Tcl interpreter. Once body has been executed then
test is evaluated again, and the process repeats until eventually test evaluates to a false boolean value. Continue commands may be exe-
cuted inside body to terminate the current iteration of the loop, and break commands may be executed inside body to cause immediate termi-
nation of the while command. The while command always returns an empty string.
Note: test should almost always be enclosed in braces. If not, variable substitutions will be made before the while command starts execut-
ing, which means that variable changes made by the loop body will not be considered in the expression. This is likely to result in an
infinite loop. If test is enclosed in braces, variable substitutions are delayed until the expression is evaluated (before each loop iter-
ation), so changes in the variables will be visible. For an example, try the following script with and without the braces around $x<10:
set x 0
while {$x<10} {
puts "x is $x"
incr x
}
EXAMPLE
Read lines from a channel until we get to the end of the stream, and print them out with a line-number prepended:
set lineCount 0
while {[gets $chan line] >= 0} {
puts "[incr lineCount]: $line"
}
SEE ALSO
break(n), continue(n), for(n), foreach(n)
KEYWORDS
boolean value, loop, test, while
Tcl while(n)