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Diffstat (limited to 'doc/gawk.texi')
| -rw-r--r-- | doc/gawk.texi | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/doc/gawk.texi b/doc/gawk.texi index 324e8eaf..94e7abbf 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -12710,10 +12710,19 @@ The parent process ID of the current process. The value of the @code{getuid()} system call. @item PROCINFO["sorted_in"] -If this element exists in @code{PROCINFO}, -@emph{no matter what its value}, -then @command{gawk} will cause @samp{for(i in arr) @dots{}} loops -to traverse the array indices in sorted order. +If this element exists in @code{PROCINFO}, its value controls the +order in which array indices will be processed by +@samp{for(i in arr) @dots{}} loops. +A value of @code{"ascending index string"}, which may be shortened to +@code{"ascending index"} or just @code{"ascending"}, will result in either +case sensitive or case insensitive ascending order depending upon +the value of @code{IGNORECASE}. +A value of @code{"descending index string"}, which may be shortened in +a similar manner, will result in the opposite order. +The value @code{"unsorted"} is also recognized, yielding the default +result of arbitrary order. Any other value will be ignored, and +warned about (at the time of first @samp{for(in in arr) @dots{}} +execution) when lint checking is enabled. @xref{Scanning an Array}, for more information. @item PROCINFO["strftime"] @@ -13379,17 +13388,16 @@ reach them. Similarly, changing @var{var} inside the loop may produce strange results. It is best to avoid such things. As an extension, @command{gawk} makes it possible for you to -loop over the elements of an array in order, sorted by index. -Sorting is based on string comparison (since all array indices are -strings), and you cannot control the style of sorting; it is always -from lowest to highest (@code{"A"} before @code{"B"}). -To enable this feature, create the array element +loop over the elements of an array in order, based on the value of @code{PROCINFO["sorted_in"]} (@pxref{Auto-set}). -The value of this element does not -matter; @command{gawk} only tests if the element with this index -exists in @code{PROCINFO} or not. -This extension is disabled in POSIX mode, since the @code{PROCINFO} -array is not special in that case. For example: +At present two sorting options are available: @code{"ascending +index string"} and @code{"descending index string"}. They can be +shortened by omitting @samp{string} or @samp{index string}. The value +@code{"unsorted"} can be used as an explicit ``no-op'' and yields the same +result as when @code{PROCINFO["sorted_in"]} has no value at all. If the +index strings contain letters, the value of @code{IGNORECASE} affects +the order of the result. This extension is disabled in POSIX mode, +since the @code{PROCINFO} array is not special in that case. For example: @example $ @kbd{gawk 'BEGIN @{} @@ -13401,7 +13409,7 @@ $ @kbd{gawk 'BEGIN @{} @print{} 4 4 @print{} 3 3 $ @kbd{gawk 'BEGIN @{} -> @kbd{ PROCINFO["sorted_in"]++} +> @kbd{ PROCINFO["sorted_in"] = "ascending index"} > @kbd{ a[4] = 4} > @kbd{ a[3] = 3} > @kbd{ for (i in a)} @@ -30341,6 +30349,9 @@ Characters used within a regexp that do not stand for themselves. Instead, they denote regular expression operations, such as repetition, grouping, or alternation. +@item No-op +An operation that does nothing. + @item Null String A string with no characters in it. It is represented explicitly in @command{awk} programs by placing two double quote characters next to |