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Size: 484
Comment:
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Size: 830
Comment: what if $varname == "length" :-(
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| The fastest way, not requiring external programs (but usable only with ["BASH"] and KornShell): | The fastest way, not requiring external programs (but usable only with [[BASH]] and KornShell): |
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| or | or for Bourne shells: |
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| ({{{expr}}} prints the number of characters matching the pattern {{{.*}}}, which is the length of the string) | ({{{expr}}} prints the number of characters matching the pattern {{{.*}}}, which is the length of the string.) |
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| or | or: |
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| (for a BSD/GNU version of {{{expr}}}. Do not use this, because it is not ["POSIX"]). | (BSD/GNU {{{expr}}} only) This second version is not specified in [[POSIX]], so is not portable across all platforms. However, if {{{$varname}}} expands to {{{"length"}}}, the first version will fail with BSD/GNU {{{expr}}}. {{{ ${#arrayname[@]} }}} Returns the Number of Elements in an Array. {{{ ${#arrayname[i]} }}} Returns the length of the Arrays Element i. ---- CategoryShell |
Is there a function to return the length of a string?
The fastest way, not requiring external programs (but usable only with BASH and KornShell):
${#varname}or for Bourne shells:
expr "$varname" : '.*'
(expr prints the number of characters matching the pattern .*, which is the length of the string.)
or:
expr length "$varname"
(BSD/GNU expr only)
This second version is not specified in POSIX, so is not portable across all platforms.
However, if $varname expands to "length", the first version will fail with BSD/GNU expr.
${#arrayname[@]}Returns the Number of Elements in an Array.
${#arrayname[i]}Returns the length of the Arrays Element i.