Built-in Variables that Control `awk'
=====================================

   This is a list of the variables which you can change to control how
`awk' does certain things.

`CONVFMT'
     This string is used by `awk' to control conversion of numbers to
     strings (see Conversion of Strings and Numbers: Conversion.).
     It works by being passed, in effect, as the first argument to the
     `sprintf' function.  Its default value is `"%.6g"'.  `CONVFMT' was
     introduced by the POSIX standard.

`FIELDWIDTHS'
     This is a space separated list of columns that tells `gawk' how to
     manage input with fixed, columnar boundaries.  It is an
     experimental feature that is still evolving.  Assigning to
     `FIELDWIDTHS' overrides the use of `FS' for field splitting.
     See Reading Fixed-width Data: Constant Size, for more
     information.

     If `gawk' is in compatibility mode (see Invoking `awk': Command Line.), then `FIELDWIDTHS' has no special meaning, and field
     splitting operations are done based exclusively on the value of
     `FS'.

`FS'
     `FS' is the input field separator (*note Specifying how Fields are
     Separated: Field Separators.).  The value is a single-character
     string or a multi-character regular expression that matches the
     separations between fields in an input record.

     The default value is `" "', a string consisting of a single space.
     As a special exception, this value actually means that any
     sequence of spaces and tabs is a single separator.  It also causes
     spaces and tabs at the beginning or end of a line to be ignored.

     You can set the value of `FS' on the command line using the `-F'
     option:

          awk -F, 'PROGRAM' INPUT-FILES

     If `gawk' is using `FIELDWIDTHS' for field-splitting, assigning a
     value to `FS' will cause `gawk' to return to the normal,
     regexp-based, field splitting.

`IGNORECASE'
     If `IGNORECASE' is nonzero, then *all* regular expression matching
     is done in a case-independent fashion.  In particular, regexp
     matching with `~' and `!~', and the `gsub' `index', `match',
     `split' and `sub' functions all ignore case when doing their
     particular regexp operations.  *Note:* since field splitting with
     the value of the `FS' variable is also a regular expression
     operation, that too is done with case ignored.  
See Case-sensitivity in Matching: Case-sensitivity.

     If `gawk' is in compatibility mode (see Invoking `awk': Command Line.), then `IGNORECASE' has no special meaning, and regexp
     operations are always case-sensitive.

`OFMT'
     This string is used by `awk' to control conversion of numbers to
     strings (see Conversion of Strings and Numbers: Conversion.) for
     printing with the `print' statement.  It works by being passed, in
     effect, as the first argument to the `sprintf' function.  Its
     default value is `"%.6g"'.  Earlier versions of `awk' also used
     `OFMT' to specify the format for converting numbers to strings in
     general expressions; this has been taken over by `CONVFMT'.

`OFS'
     This is the output field separator (see Output Separators.).
     It is output between the fields output by a `print' statement.  Its
     default value is `" "', a string consisting of a single space.

`ORS'
     This is the output record separator.  It is output at the end of
     every `print' statement.  Its default value is a string containing
     a single newline character, which could be written as `"\n"'.
     (See Output Separators.)

`RS'
     This is `awk''s input record separator.  Its default value is a
     string containing a single newline character, which means that an
     input record consists of a single line of text.  (*Note How Input
     is Split into Records: Records.)

`SUBSEP'
     `SUBSEP' is the subscript separator.  It has the default value of
     `"\034"', and is used to separate the parts of the name of a
     multi-dimensional array.  Thus, if you access `foo[12,3]', it
     really accesses `foo["12\0343"]' (see Multi-dimensional Arrays: Multi-dimensional.).