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For more details on <tt>for</tt> and <tt>IFS</tt>, see [[bash Environment Variables#IFS|IFS]]. | For more details on <tt>for</tt> and <tt>IFS</tt>, see [[bash Environment Variables#IFS|IFS]]. | ||
=Iterating over a File List= | |||
Also see [[Bash Concepts#Globbing|Globbing]]. |
Revision as of 05:27, 5 March 2016
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 ${i}; done
Note the use of ";"
Iterating over Lines in the Same bash Process
IFS="$(printf '\n\r')" for line in $(cat ./file.txt); do echo "${line}" done IFS="$(printf ' \t\n')"
For more details on for and IFS, see IFS.
Iterating over a File List
Also see Globbing.