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Diffstat (limited to 'doc/gawktexi.in')
| -rw-r--r-- | doc/gawktexi.in | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/doc/gawktexi.in b/doc/gawktexi.in index 0c32c9f5..6f9ebc5c 100644 --- a/doc/gawktexi.in +++ b/doc/gawktexi.in @@ -606,6 +606,9 @@ particular records in a file and perform operations upon them. This is an advanced method of input. * Conversion:: The conversion of strings to numbers and vice versa. +* Strings And Numbers:: How @command{awk} Converts Between + Strings And Numbers. +* Locale influences conversions:: How the locale may affect conversions. * All Operators:: @command{gawk}'s operators. * Arithmetic Ops:: Arithmetic operations (@samp{+}, @samp{-}, etc.) @@ -10153,6 +10156,19 @@ sequences @node Conversion @subsection Conversion of Strings and Numbers +Number to string and string to number conversion are generally +straightforward. There can be subtleties to be aware of; +this @value{SECTION} discusses this important facet of @command{awk}. + +@menu +* Strings And Numbers:: How @command{awk} Converts Between Strings And + Numbers. +* Locale influences conversions:: How the locale may affect conversions. +@end menu + +@node Strings And Numbers +@subsubsection How @command{awk} Converts Between Strings And Numbers + @cindex converting, strings to numbers @cindex strings, converting @cindex numbers, converting @@ -10222,6 +10238,7 @@ b = a "" @code{b} has the value @code{"12"}, not @code{"12.00"}. @value{DARKCORNER} +@sidebar Pre-POSIX @command{awk} Used @code{OFMT} For String Conversion @cindex POSIX @command{awk}, @code{OFMT} variable and @cindex @code{OFMT} variable @cindex portability, new @command{awk} vs.@: old @command{awk} @@ -10234,6 +10251,10 @@ conversion from the semantics of printing. Both @code{CONVFMT} and @code{OFMT} have the same default value: @code{"%.6g"}. In the vast majority of cases, old @command{awk} programs do not change their behavior. @xref{Print}, for more information on the @code{print} statement. +@end sidebar + +@node Locale influences conversions +@subsubsection Locales Can Influence Conversion Where you are can matter when it comes to converting between numbers and strings. The local character set and language---the @dfn{locale}---can @@ -12012,6 +12033,7 @@ of others let you control how @command{awk} behaves. Numbers are automatically converted to strings, and strings to numbers, as needed by @command{awk}. Numeric values are converted as if they were formatted with @code{sprintf()} using the format in @code{CONVFMT}. +Locales can influence the conversions. @item @command{awk} provides the usual arithmetic operators (addition, @@ -29506,7 +29528,7 @@ the following computes 5<superscript>4<superscript>3<superscript>2</superscript></superscript></superscript>, @c @end docbook the result of which is beyond the -limits of ordinary @command{gawk} numbers: +limits of ordinary hardware double-precision floating point values: @example $ @kbd{gawk -M 'BEGIN @{} @@ -29614,7 +29636,7 @@ source code constants.) Support for the special IEEE 754 floating point values ``Not A Number'' (NaN), positive Infinity (``inf'') and negative Infinity (``@minus{}inf''). In particular, the format for these values is as specified by the ISO 1999 -C standard, which ignores case and can allow machine-dependent additional +C standard, which ignores case and can allow implementation-dependent additional characters after the @samp{nan} and allow either @samp{inf} or @samp{infinity}. @end itemize |