Linux Commands: Declare variables and give them attributes


declare-Linux Command

declare command- Declare variables and give them attributes

Syntax: declare [-afFrxi] [-p] [name[=value]]

 

Description: The declare command can be helpful in identifying variables, environmental or otherwise. This can be especially useful with arrays.
-r readonly
(declare -r var1 works the same as readonly var1)
This is the rough equivalent of the C const type qualifier. An attempt to change the value of a readonly variable fails with an error message.
-i integer
Certain arithmetic operations are permitted for declared integer variables without the need for expr or let.
-a array
The variable indices will be treated as an array.
-f function(s)
A declare -f line with no arguments in a script causes a listing of all the functions previously defined in that script.
A declare -f function_name in a script lists just the function named.
-x export
This declares a variable as available for exporting outside the environment of the script itself.
-x var=$value
The declare command permits assigning a value to a variable in the same statement as setting its properties.

Example:

Related:

Other Linux Commands:
alias , break , builtin , cal , case , cat , cd , cfdisk , chgrp , chmod , chown , chroot , cksum , cmp , comm , continue , cp , cron , crontab , csplit , cut , date , dc , dd , declare , df , diff , diff3 , dir , dircolors , dirname , dirs , du , echo , egrep , enable , env , eval , exec , expand , export , expr , factor , false , fdformat , fdisk , fgrep , find , fmt , fold , for , fsck , function , getopts , hash , hashcharacter , head , history , hostname , id , if , import , install , join , kill , less , let , ln , local , locate , logname , logout , lpc , lpr , lprm , ls , m4 , man , mbadblocks , mkdir , mkfifo , mknod , more , mount , mtools , mv , nice , nl , nohup , passwd , paste , period , popd , pr , printf , ps , pushd , pwd , quota , quotacheck , quotactl , ram , rcp , read , readonly , return , rm , rmdir , rsync , Run , sdiff , sed , select , seq , set , shift , shopt , shutdown , sleep , sort , split , su , sum , symlink , sync , tac , tail , tar , tee , Test , time , times , top , touch , tr , traceroute , true , tsort , tty , Type , ulimit , umask , uname , Unexpand , uniq , units , unset , unshar , until , useradd , usermod , users , uuencode , watch , wc , whereis , which , while , who , xargs , yes ,
Live2Support.com :
Product - Benefits - Features - How Does it Works - Pricing - SSL Certificates - Signup - Contactus - Login - Submit Resources