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Diffstat (limited to 'doc/gawk.texi')
| -rw-r--r-- | doc/gawk.texi | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/doc/gawk.texi b/doc/gawk.texi index c3ec64e5..7d5aa4dc 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -11990,6 +11990,21 @@ When used in numeric conversions, strongly typed regexp variables convert to zero. When used in string conversions, they convert to the string value of the original regexp text. +There is an additional, interesting corner case. When used as the third +argument to @code{sub()} or @code{gsub()}, they retain their type. Thus, +if you have something like this: + +@example +re = @/don't panic/ +sub(/don't/, "do", re) +print typeof(re), re +@end example + +@noindent +then @code{re} retains its type, but now attempts to match the string +@samp{do panic}. This provides a (very indirect) way to create regexp-typed +variables at runtime. + @node Variables @subsection Variables @@ -18682,6 +18697,9 @@ numeric values less than one as if they were one. If no @var{target} is supplied, use @code{$0}. Return the modified string as the result of the function. The original target string is @emph{not} changed. +The returned value is @emph{always} a string, even if the original +@var{target} was a number or a regexp value. + @code{gensub()} is a general substitution function. Its purpose is to provide more features than the standard @code{sub()} and @code{gsub()} functions. @@ -18730,7 +18748,8 @@ substitution is performed. If @var{how} is zero, @command{gawk} issues a warning message. If @var{regexp} does not match @var{target}, @code{gensub()}'s return value -is the original unchanged value of @var{target}. +is the original unchanged value of @var{target}. Note that, as mentioned +above, the returned value is a string, even if @var{target} was not. @item @code{gsub(@var{regexp}, @var{replacement}} [@code{, @var{target}}]@code{)} @cindexawkfunc{gsub} |