gawk: Advanced Features Summary
12.6 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.