Variable Initialize Post: 80378

Sponsored Content

Top Forums Shell Programming and Scripting Variable Initialize Post 80378 by blowtorch on Sunday 7th of August 2005 01:40:33 PM

08-07-2005

Registered User

Quote:

Originally Posted by coolbudy

Hi, i m trying to loop a variable value, Basically i m reading variable value from an input file and using in rest of the program. Bu my problem is when i first time read value and assign to variable it works fine, but in second read it concatinate second value to first value with a LF. I want to use one value at a time. Here is what i am doing

carrier_id=`cat ${cnt_path}mpd_rxsh_carrier_id.dat | head -${i}`
Value::
1st read
253090
2nd read
253090
253029
3rd read
253090
253029
255055

Your error is quite obvious. Your loop variable is 'i', and as the value of i increases, head -${i} returns more and more lines. Let me explain.

At your first pass through the loop, the value of i is 1. You get the first line. So far so good. At the second pass the value of i becomes 2 and head -${i} becomes head -2, which returns the first two lines.. this will continue as long as the value of i increases.

If you want to read the value of carrier id from the file into variable carrier_id, you have to use

Code:

while read carrier_id;do
..
# do your stuff here
..
done < ${cnt_path}mpd_rxsh_carrier_id.dat

blowtorch

View Public Profile for blowtorch

Find all posts by blowtorch

10 More Discussions You Might Find Interesting

1. Programming

variable initialize question

I have a question about C program for Unix: Do we have to intialize every variable before we use them in C? I thought we have to untill I found some programs are not intialize the variable before they were used.

2. UNIX for Dummies Questions & Answers

nslookup *** Can't initialize resolver

Has anyone seen this message before? I have a DNS problem. Recently DNS has been moved to two new servers, which I can ping. I changed the /etc/resolv.conf to point to these boxes but now I get the *** Can't initialize resolver message. Any ideas?

3. SCO

initialize lp job

I use SCO UNIX from 2 years I need a command or procedure to make all log files empty and restart all counters like lp job number :( :confused: :(

4. HP-UX

Can not initialize the floppy

Hello Everyone, Has anyboby ever come across the problem when fd refuses to get initialised. I try to use mediainit command, the fd is being accessed (the fd's LIT is green for some secs) but then I get the message - "Initialize media command failed - permission denied" I checked the diskette,...

5. Shell Programming and Scripting

initialize file to zero

hi can anyone tell how to initialize a file to zero

6. Shell Programming and Scripting

Initialize a variable

Hi All, Please can you advise on how can I initialize a variable with a line. Suppose i want to initialize x with line redirects.www.virginatlantic.com.conf Best Regards, Shazin

7. SCO

How to initialize tape drive

Hi all Just connected a SCSI tape drive to our ScoUnix server running Unixware 7.0.1. The ID assigned to it is 3. When I open ArcServe it is saying that tape drive is not found and I cannot configure it. How can I make the tape drive accessible to the system? Thanks!

8. Red Hat

Fedora Initialize disklabel

What is the point of Fedora Initialize disklabel and how does it work? How do I check what my current Fedora's disklabel is initialized to?

9. Shell Programming and Scripting

initialize a variable only once

hi, i have a script which needs to be run every 10 minutes.This is achieved using crontab utility, it is checking Number of calls on a service... if number of calls are not increasing then it will stop the service else do nothing. Now in the script, i fetch the current value in variable...

10. UNIX for Dummies Questions & Answers

Initialize Variable Using awk Expression

Hello All, What i am trying to do is read the input file delimited by pipe and do further logic like simulating the for loop but using awk not sure if this a right approach but as i was told doing "for i in `cat $file`" is an over kill so trying to replicate the same thing using awk script below....

LEARN ABOUT SUSE

head

HEAD(1) 							   User Commands							   HEAD(1)

NAME

       head - output the first part of files

SYNOPSIS

       head [OPTION]... [FILE]...

DESCRIPTION

       Print  the first 10 lines of each FILE to standard output.  With more than one FILE, precede each with a header giving the file name.  With
       no FILE, or when FILE is -, read standard input.

       Mandatory arguments to long options are mandatory for short options too.

       -c, --bytes=[-]N
	      print the first N bytes of each file; with the leading `-', print all but the last N bytes of each file

       -n, --lines=[-]N
	      print the first N lines instead of the first 10; with the leading `-', print all but the last N lines of each file

       -q, --quiet, --silent
	      never print headers giving file names

       -v, --verbose
	      always print headers giving file names

       --help display this help and exit

       --version
	      output version information and exit

       N may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P,
       E, Z, Y.

AUTHOR

       Written by David MacKenzie and Jim Meyering.

REPORTING BUGS

       Report head bugs to bug-coreutils@gnu.org
       GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
       General help using GNU software: <http://www.gnu.org/gethelp/>

COPYRIGHT

       Copyright (C) 2009 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

       The  full documentation for head is maintained as a Texinfo manual.  If the info and head programs are properly installed at your site, the
       command

	      info coreutils 'head invocation'

       should give you access to the complete manual.

GNU coreutils 7.1						     July 2010								   HEAD(1)

10 More Discussions You Might Find Interesting

1. Programming

variable initialize question

Discussion started by: whatisthis

2. UNIX for Dummies Questions & Answers

nslookup *** Can't initialize resolver

Discussion started by: korfnz

3. SCO

initialize lp job

Discussion started by: sharina

4. HP-UX

Can not initialize the floppy

Discussion started by: Andrey Malishev