Bash for

From NovaOrdis Knowledge Base
Revision as of 00:12, 1 March 2016 by Ovidiu (talk | contribs)
Jump to navigation Jump to search

External

Internal

Overview

The for built-in command expand words, and execute commands once for each member in the resultant list, with i bound to the current member.

   for i in words; do commands; done

Alternatively, for:

   for i do commands; done

commands executes for each positional parameter (as if in "$@" had been specified.

Yes another alternative form:

    for (( i=0; i<${#names[@]}; i++ )); do
        local name=${names[${i}]}
        echo "${name}"
    done

Iterating through $1, $2, $3 ...

     for i do
         echo ${i}
     done

Iterating through a space separated list

    s="a b c"
    for i in ${s}
        do
            echo ${i}
        done

or

     s="a b c"
     for i in ${s}; do echo ${i}; done

Note the use of ";"


Iterating over Lines in the Same bash Process

IFS=

For more details on for and IFS, see IFS.