Bourne Shell: Difference between revisions
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(Examples marked "Works with: Bourne Shell" should work in any of the Bourne-compatible shells.) |
(Show a bug with here documents.) |
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In 2009, [[wp:Computerworld|Computerworld]] published an in-depth interview with Steve Bourne, ''[http://www.computerworld.com.au/article/279011/a-z_programming_languages_bourne_shell_sh/ The A-Z of Programming Languages: Bourne shell, or sh]'', which details the Bourne shell origins and design decisions. |
In 2009, [[wp:Computerworld|Computerworld]] published an in-depth interview with Steve Bourne, ''[http://www.computerworld.com.au/article/279011/a-z_programming_languages_bourne_shell_sh/ The A-Z of Programming Languages: Bourne shell, or sh]'', which details the Bourne shell origins and design decisions. |
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== Bugs == |
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Bourne Shell and Heirloom Shell have problems with here documents. Here is one such problem. A substitution, inside a here document, inside backquotes, inside double quotes, does insert too many backslashes. |
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<lang bash>f() { |
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cat <<! |
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here $1 |
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! |
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} |
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expr "`f string`" |
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# Output from Bourne Shell: here \s\t\r\i\n\g |
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# Correct output: here string</lang> |
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The workaround is to move the backquotes to an assignment. |
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<lang bash>f() { |
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cat <<! |
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here $1 |
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! |
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} |
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var=`f string` |
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expr "$var" |
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# Output: here string</lang> |
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