File: gawk.info,  Node: Advanced Features Summary,  Prev: Extension Philosophy,  Up: Advanced Features

12.9 Summary
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   * The '--non-decimal-data' option causes 'gawk' to treat octal- and
     hexadecimal-looking input data as octal and hexadecimal.  This
     option should be used with caution or not at all; use of
     'strtonum()' is preferable.  Note that this option may disappear in
     a future version of 'gawk'.

   * You can take over complete control of sorting in 'for (INDX in
     ARRAY)' array traversal by setting 'PROCINFO["sorted_in"]' to the
     name of a user-defined function that does the comparison of array
     elements based on index and value.

   * Similarly, you can supply the name of a user-defined comparison
     function as the third argument to either 'asort()' or 'asorti()' to
     control how those functions sort arrays.  Or you may provide one of
     the predefined control strings that work for
     'PROCINFO["sorted_in"]'.

   * You can use the '|&' operator to create a two-way pipe to a
     coprocess.  You read from the coprocess with 'getline' and write to
     it with 'print' or 'printf'.  Use 'close()' to close off the
     coprocess completely, or optionally, close off one side of the
     two-way communications.

   * By using special file names with the '|&' operator, you can open a
     TCP/IP (or UDP/IP) connection to remote hosts on the Internet.
     'gawk' supports both IPv4 and IPv6.

   * You can generate statement count profiles of your program.  This
     can help you determine which parts of your program may be taking
     the most time and let you tune them more easily.  Sending the
     'USR1' signal while profiling causes 'gawk' to dump the profile and
     keep going, including a function call stack.

   * You can also just "pretty-print" the program.

   * Persistent memory allows you to preserve the values of variables
     and arrays between runs of 'gawk'.  This feature is currently
     experimental.

   * New features should be developed using the extension mechanism if
     possible; they should be added to the core interpreter only as a
     last resort.