In POSIX sh, arrays are undefined.
Problematic code:
#!/bin/sh
x=( foo bar "Hello World" )
for word in "${x[@]}"
do
touch "$word.dat"
done
Correct code:
Consider switching to a shell that does support arrays, such as bash
or ksh
, by changing the shebang.
Alternatively, if you only need a single array at a time, you may be able to rewrite to use the positional parameters:
set -- foo bar "Hello World"
for word in "$@"
do
touch "$word.dat"
done
or strings with carefully chosen delimiters:
x='foo
bar
Hello World
'
printf '%s' "$x" |
while IFS='' read -r word
do
touch "$word.dat"
done
Rationale:
Arrays are specific to Bash and Ksh, but you are using them in a script declared to run with sh
or dash
. These shells do not support arrays at all. You should either switch to Bash/Ksh, or rewrite the script to not use arrays.
There are no great replacements, especially not that can be mechanically applied, but using the positional parameters or a delimited string works in many cases, as shown in the examples.
Exceptions:
None.
Related resources:
- Help by adding links to BashFAQ, StackOverflow, man pages, POSIX, etc!
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Installation
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Usage
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Integrating and extending
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