for command

Synopis

for <variable> in <items>; do <commands>; done

Description

The for command is used to loop over a list of values and execute a series of commands for each of these.

The counter variable of the loop is a shell variable. Please, keep in mind that an environment variable takes precedence over a shell variable of the same name.

variable

name of the counter variable

items

space separated item list

commands

commands to execute

Example

=> setenv c
=> for c in 1 2 3; do echo item ${c}; done
item 1
item 2
item 3
=> echo ${c}
3
=> setenv c x
=> for c in 1 2 3; do echo item ${c}; done
item x
item x
item x
=>

The first line ensures that there is no environment variable c. Hence in the first loop the shell variable c is printed.

After defining an environment variable of name c it takes precedence over the shell variable and the environment variable is printed.

Return value

The return value $? after the done statement is the return value of the last statement executed in the loop.

=> for i in true false; do ${i}; done; echo $?
1
=> for i in false true; do ${i}; done; echo $?
0