runawk_modules(3)

NAME
runawk - wrapper for AWK interpreter

MODULES
runawk provides dozens of modules. Below is the documentation for them.

  CR_in.awk
As the name of this module says (_in suffix) this module reads and optionally changes input lines.

Carriage-Return symbol at the end of input lines is removed. This symbol usually appears in Windows text files. If you want to adapt your script to accept windows files on input, just put

    #use "CR_in.awk"

in the very beginning of your script.

  abort.awk

abort (MSG, [EXIT_STATUS])
    print MSG to stderr and exits program with EXIT_STATUS. EXIT_STATUS defaults to 1.

  abs.awk

abs (V)
    return absolute value of V.

  alt_assert.awk

assert (CONDITION, MSG, STATUS)
    print an error message MSG to standard error and terminates the program with STATUS exit code if CONDITION is false.

  alt_getopt.awk

getopt(SHORT_OPTS)
    This function processes ARGV array and returns TRUE if option is received, received option is saved in 'optopt' variable, option argument (if any) is saved in 'optarg' variable. Long options (like --help or --long-option) present in GNU libc and BSD systems are also supported.

    NOTE: alt_getopt.awk module follows rules from SUS/POSIX "Utility Syntax Guidelines"

  alt_join.awk

join_keys (HASH, SEP)
    return string consisting of all keys from HASH separated by SEP.

join_values (HASH, SEP)
    return string consisting of all values from HASH separated by SEP.

join_by_numkeys (ARRAY, SEP [, START [, END]])
    return string consisting of all values from ARRAY separated by SEP. Indices from START (default: 1) to END (default: +inf) are analysed. Collecting values is stopped on index absent in ARRAY.

  backslash_in.awk
As the name of this module (_in suffix) says this module reads and optionally changes input lines.

Backslash character at the end of line is treated as a sign that current line is continued on the next one. Example is below.

Input:
    a b c\
    d e f g
    a
    b
    e\
      f

What your program using backslash_in.awk will obtain:
    a b cd e f g
    a
    b
    e f

  basename.awk

basename (PATH)
    return filename portion of the PATH (the same as dirname(3))

See example/demo_basename for the sample of usage

  braceexpand.awk

braceexp(STRING)
    shell-like brace expansion.

    For example: print braceexpand("ab{,22{,7,8}}z{8,9}")
      -| abz8 abz9 ab22z8 ab22z9 ab227z8 ab227z9 ab228z8 ab228z9

  dirname.awk

dirname (PATH)
    return dirname portion of the PATH (the same as dirname(3))

See example/demo_dirname for the sample of usage

  embed_str.awk
This module reads a program's file, find .begin-str/.end-str pairs and reads lines between them.

EMBED_STR - Associative array with string index

Example:
 Input:
  .begin-str mymsg
   Line1
   Line2
  .end-str
 Output (result)
  EMBED_STR ["mymsg"]="Line1\nLine2"

See example/demo_embed_str for the sample of usage

  exitnow.awk

exitnow (STATUS)
    similar to the statement 'exit' but do not run END sections.

  fieldwidth.awk
By default AWK interpreter splits input lines into tokens according to regular expression that defines "spaces" between them using special variable FS. Sometimes it is useful to define a fixed-size fields for tokens. This is what this module is for. The functionality of fieldwidths.awk is very close to GNU awk's FIELDWIDTHS variable.

fieldwidths(STRING, FW)
    extracts substrings from STRING according to FW from the left to the right and assigns $1, $2 etc. and NF variable. FW is a space separated list of numbers that specify fields widths.

fieldwidths0(FW)
    Does the the same as `fieldwidths' function but splits $0 instead.

FW  global variable. If it is set to non-empty string, all input lines are split automatically and the value of variable FS is ignored in this case.

See example/demo_fieldwidths for the sample of usage

  ftrans_in.awk
beginfile() function provided by user is called before file reading

endfile() function provided by user is called after file reading

  ord.awk

ord (CHAR)
    return numeral code of CHAR

chr (CODE)
    return symbol from the CODE

  glob.awk

glob2ere (PATTERN)
    convert glob PATTERN (http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_13) to equivalent extended regular expression (http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap09.html#tag_09_04)

  has_prefix.awk

has_prefix (STRING, PREFIX)
    return TRUE if STRING begins with PREFIX

See example/demo_has_prefix for the sample of usage

  has_suffix.awk

has_suffix(STRING, SUFFIX)
    return TRUE if STRING ends with SUFFIX

See example/demo_has_suffix for the sample of usage

  heapsort.awk

heapsort (src_array, dest_remap, start, end)
    The content of `src_array' is sorted using awk's rules for comparing values. Values with indices in range [start, end] are sorted. `src_array' array is not changed. Instead dest_remap array is generated such that

      Result:
        src_array [dest_remap [start]] <=
           <= src_array [dest_remap [start+1]] <=
           <= src_array [dest_remap [start+2]] <= ... <=
           <= src_array [dest_remap [end]]

      `heapsort' algorithm is used.
    Examples: see demo_heapsort and demo_heapsort2 executables.

heapsort_values (src_hash, dest_remap)
    The same as `heapsort' described above, but hash values are sorted.

      Result:
        src_array [dest_remap [1]] <=
           <= src_array [dest_remap [2]] <=
           <= src_array [dest_remap [3]] <= ... <=
           <= src_array [dest_remap [count]]

      `count', a number of elements in `src_hash', is a return value.

    Examples: see demo_heapsort3 executable.

heapsort_indices (src_hash, dest_remap)
    The same as `heapsort' described above, but hash indices are sorted.

      Result:
        dest_remap [1] <=
           <= dest_remap [2] <=
           <= dest_remap [3] <= ... <=
           <= dest_remap [count]

      `count', a number of elements in `src_hash', is a return value.

    Examples: demo_ini

heapsort_fields (dest_remap, [start [, end [, strnum]]])
    The same as function "heapsort0" but $1, $2... array is sorted. Note that $1, $2... are not changed, but dest_remap array is filled in! The variable "start" default to 1, "end" -- to NF. If "strnum" is set to 1, values are forcibly compared as strings. If "strnum" is set to 2, values are forcibly compared as numbers.

heapsort0 ([start [, end [, strnum]]])
    The same as "heapsort_fields" but $1, $2... are changed.

  ini.awk
This module provides functions for manipulating .ini files. See example/demo_ini for the sample of use.

read_inifile(FILENAME, RESULT [, SEPARATOR])
    Reads .ini file FILENAME and fills array RESULT, e.g. RESULT [<section5><SEPARATOR><name6>] = <value5.6> etc. If SEPARATOR is not specified, `.' symbols is used by default.

Features:

  - spaces are allowed everywhere, i.e. at the beginning and end of
    line, around `=' separator. THEY ARE STRIPPED!
  - comment lines start with `;' or `#' sign. Comment lines are ignored.
  - values can be surrounded by signle or double quote. In this case
    spaces are presenrved, otherwise they are removed from
    beginning and at the end of line and replaced with single space
    in the middle of the line.
  - Escape character are not supported (yet?).

  init_getopt.awk
Initialization step for power_getopt.awk module. In some cases it makes sense to process options in a while() loop. This module allows doing this. See the documentation about how options are initialized in power_getopt.awk module.

print_help ()
    display help message.

  io.awk
This module provides a number of IO functions.

is_file(FILENAME)
    returns 1 if the specified FILENAME is a regular file or 0 otherwise.

is_socket(FILENAME)
    returns 1 if the specified FILENAME is a socket or 0 otherwise.

is_dir(FILENAME)
    returns 1 if the specified FILENAME
     is a dir or 0 otherwise.

is_exec(FILENAME)
    returns 1 if the specified FILENAME is executable or 0 otherwise.

is_fifo(FILENAME)
    returns 1 if the specified FILENAME is a FIFO or 0 otherwise.

is_blockdev(FILENAME)
    returns 1 if the specified FILENAME is a block special file or 0 otherwise.

is_chardev(FILENAME)
    returns 1 if the specified FILENAME is a character special file or 0 otherwise.

is_symlink(FILENAME)
    returns 1 if the specified FILENAME is a symlink or 0 otherwise.

file_size(FILENAME, USE_STAT_NOT_LSTAT)
    returns the size of the specified FILENAME. If USE_STAT_NOT_LSTAT is True, stat(2) is used instead of lstat(2).

      Return value:
        -2 if file doesn't exist
        -1 if file is not a regular file
        filesize otherwise

file_type(FILENAME, USE_STAT_NOT_LSTAT)
    returns a single letter that corrspond to the file type. If USE_STAT_NOT_LSTAT is True, stat(2) is used instead of lstat(2).

      Return value:
        -  --  regular file
        d  -- directory
        c  -- character device
        b  -- block device
        p  -- FIFO
        l  -- symlink
        s  -- socket

See example/demo_io for the sample of usage

  isnum.awk

isnum (NUM)
    returns 1 if an argument is a number

  match_br.awk

match_br(STRING, BR_OPEN, BR_CLOSE)
    return start position (or zero if failure) of the substring surrounded by balanced (), [], {} or similar characters Also sets RSTART and RLENGTH variables just like the standard 'match' function does

    For example:
      print match_br("A (B (), C(D,C,F (), 123))", "(", ")")
      print RSTART, RLENGTH
      -| 3
      -| 3
      -| 24

  max.awk

max, max3, max4, max5
    maximum functions

max_key(HASH, DFLT)
    returns a maximum key in HASH or DFLT if it is empty

max_value(HASH, DFLT)
    returns a maximum value in HASH or DFLT if it is empty

key_of_max_value(HASH, DFLT)
    returns A KEY OF maximum value in HASH or DFLT if it is empty

  min.awk

min, min3, min4, min5
    minimum functions

min_key(HASH, DFLT)
    returns a minimum key in HASH or DFLT if it is empty

min_value(HASH, DFLT)
    returns a minimum value in HASH or DFLT if it is empty

key_of_min_value(HASH, DFLT)
    returns A KEY OF minimum value in HASH or DFLT if it is empty

  modinfo.awk
This module provides the following variables

MODC
    A number of modules (-f <filename>) passed to an awk interpreter

MODV
    Array with [0..MODC) indexes of those modules

MODMAIN
    Path to the main module, i.e. program filename

See example/demo_modinfo for the sample of usage

  multisub.awk

multisub(STRING, SUBST_REPLS[, KEEP])
    is a substitution function. It searches for a list of substrings, specified in SUBST_REPL in a left-most longest order and (if found) replaces found fragments with appropriate replacement. SUBST_REPL format: "SUBSTRING1:REPLACEMENT1 SUBSTRING2:REPLACEMENT2...". Three spaces separate substring:replacement pairs from each other. If KEEP is specified and some REPLACEMENT(N) is equal to it, then appropriate SUBSTRING(N) is treated as a regular expression and matched text is kept as is, i.e. not changed.

    For example:
         print multisub("ABBABBBBBBAAB", "ABB:c BBA:d AB:e")
         |- ccBBde

  pow.awk

pow (X, Y)
    returns the value of X to the exponent Y

  power_getopt.awk
power_getopt.awk module provides a very easy way to add options to AWK application and follows rules from SUS/POSIX "Utility Syntax Guidelines"

power_getopt.awk analyses '.begin-str help/.end-str' section in AWK program (main module), and processes options specified there. The following strings mean options:
 -X single letter option
 --XXX long option
 -X|--XXX single letter option with long synonym
 =X single letter option with argument
 =-XXX long option with argument
 =X|--XXX single letter option and long synonym with argument

If --help option was applied, usage information is printed (lines between ".begin-str help" and ".end-str") replacing leading `=' character with `-'.

getarg(OPT, DEFAULT)
    returns either 1 (option OPT was applied) or 0 (OPT was not applied) for options not accepting the argument, and either specified value or DEFAULT for options accepting the argument.

    See example/demo_power_getopt for the sample of usage

  quicksort.awk

quicksort (src_array, dest_remap, start, end)
    The content of `src_array' is sorted using awk's rules for comparing values. Values with indices in range [start, end] are sorted. `src_array' array is not changed. Instead dest_remap array is generated such that

      Result:
        src_array [dest_remap [start]] <=
           <= src_array [dest_remap [start+1]] <=
           <= src_array [dest_remap [start+2]] <= ... <=
           <= src_array [dest_remap [end]]

    `quicksort' algorithm is used. Examples: see demo_quicksort and demo_quicksort2 executables

quicksort_values (src_hash, dest_remap)
    The same as `quicksort' described above, but hash values are sorted.

      Result:
        src_hash [dest_remap [1]] <=
           <= src_hash [dest_remap [2]] <=
           <= src_hash [dest_remap [3]] <= ... <=
           <= src_hash [dest_remap [count]]

    `count', a number of elements in `src_hash', is a return value. Examples: see demo_quicksort* executables.

quicksort_indices (src_hash, dest_remap)
    The same as `quicksort' described above, but hash indices are sorted.

      Result:
        dest_remap [1] <=
           <= dest_remap [2] <=
           <= dest_remap [3] <= ... <=
           <= dest_remap [count]

    `count', a number of elements in `src_hash', is a return value.

  readfile.awk

readfile(FILENAME)
    read entire file and return its content as a string

See example/demo_readfile for the sample of usage

  runcmd.awk

runcmd1 (CMD, OPTS, FILE)
    wrapper for system() function that runs a command CMD with options OPTS and one filename FILE. Unlike system(CMD " " OPTS " " FILE) the function runcmd1 handles correctly FILE containing spaces, single quote, double quote, tilde etc.

xruncmd1 (FILE)
    safe wrapper for 'runcmd1'. awk exits with error if runcmd1() function failed.

  shquote.awk

shquote(str)
    transforms the string `str' by adding shell escape and quoting characters to include it to the system() and popen() functions as an argument, so that the arguments will have the correct values after being evaluated by the shell.

    For example:
         print shquote("file name.txt")
         |- 'file name.txt'
         print shquote("'")
         |- \'
         print shquote("Peter's")
         |- 'Peter'\''s'
         print shquote("*&;<>#~")
         |- '*&;<>#~'

This module was inspired by NetBSD shquote(3)
   http://netbsd.gw.com/cgi-bin/man-cgi?shquote+3+NetBSD-current and shquote(1) by Alan Barrett
   http://ftp.sunet.se/pub/os/NetBSD/misc/apb/shquote.20080906/

  sort.awk

sort (src, dest_remap, start, end)
    Call either heapsort function from heapsort.awk (if RUNAWK_SORTTYPE environment variable is "heapsort") or quicksort from quicksort.awk (if RUNAWK_SORTTYPE is "quicksort"). Sorttype defaults to "heapsort".

sort_values (src, dest_remap)
    Call either heapsort_values function from heapsort.awk (if RUNAWK_SORTTYPE environment variable is "heapsort") or quicksort_values from quicksort.awk (if RUNAWK_SORTTYPE is "quicksort"). Sorttype defaults to "heapsort".

sort_indices (src, dest_remap)
    Call either heapsort_indices function from heapsort.awk (if RUNAWK_SORTTYPE environment variable is "heapsort") or quicksort_indices from quicksort.awk (if RUNAWK_SORTTYPE is "quicksort"). Sorttype defaults to "heapsort".

  str2regexp.awk

str2regex(STRING)
    returns a regular expression that matches given STRING

For example:
  print str2regexp("all special symbols: ^$(){}[].*+?|\\")
  -| all special symbols: [^][$][(][)][{][}][[]\][.][*][+][?][|]\\

  tmpfile.awk
This module provides a function `tmpfile' for generating temporary filenames. All these filenames are under temporary directory created (if necessary) by runawk(1) which is removed automatically during normal exit or when runawk(1) reveives SIGINT, SIGQUIT, SIGTERM, SIGHUP or SIGPIPE.

tmpfile()
    returns a temporary file name.

runawk_tmpdir
    global variable that keeps tempdir created by runawk -t

See example/demo_tmpfile for the sample of usage

  tokenre.awk
By default AWK splits input lines into tokens according to regular expression that defines "spaces" between tokens using special variable FS. In many situations it is more useful to define regular expressions for tokens themselves. This is what this module does.

tokenre(STRING, REGEXP)
    extracts substrings from STRING according to REGEXP from the left to the right and assigns $1, $2 etc. and NF variable.

tokenre0(REGEXP)
    Does the the same as `tokenre' but splits $0 instead.

splitre(STRING, ARR, REGEXP)
    The same as `tokenre' but ARR[1], ARR[2]... are assigned. A number of extracted tokens is a return value.

TRE global variable. If it is set to non-empty string, all input lines are split automatically.

  trim.awk

trim_l(STRING)
    Removes leading Tab and Space characters from STRING and returns the result.

trim_r(STRING)
    Removes Tab and Space characters at the end of STRING and returns the result.

trim_c(STRING, REPL)
    Replaces sequences of Tab and Space characters in STRING with REPL and returns the result. If REPL is not specified, it defaults to single Space character.

trim_lr(STRING)
    Equal to trim_l(trim_r(STRING))

trim_lrc(STRING, REPL)
    Equal to trim_l(trim_r(trim_c(STRING, REPL)))

See example/demo_trim for the sample of usage

  trim_in.awk
As the name of this module says (_in suffix) this module reads and potentially changes input lines.

Leading, ending spaces and/or spaces in the middle of input lines are removed depending on TRIM variable. TRIM values:
  "l" - remove leading space characters
  "r" - remove ending space characters
  "c" - remove extra space characters in the middle of input lines
  "lr" - See l and r
  "lrc" - See l, r and c
  "lc" - See l and c
  "cr" - See c and r By default TRIM variable is set to "lr". TRIM set to a single space character means no trimming.

  xclose.awk

xclose(FILE)
    safe wrapper for 'close'. awk exits with error if close() function failed.

  xgetline.awk

xgetline0([FILE])
    Safe analog to 'getline < FILE' or 'getline' (if no FILE is specified). 0 at the end means that input line is assigned to $0.

xgetline([FILE])
    Safe analog to 'getline __input < FILE' and 'getline __input' (if no FILE is specified)

In both cases "safe" means that returned value is analysed and if it is less than zero (file reading error happens) program will be terminated emmidiately with appropriate error message sent to stderr. Both functions return zero if end of file is reached or non-zero otherwise.

Example:
      while (xgetline("/etc/passwd")){
          print "user: " __input
      }

  xsystem.awk

xsystem(FILE)
    safe wrapper for 'system'. awk exits with error if system() function failed.

AUTHOR
Copyright (c) 2007-2014 Aleksey Cheusov <vle@gmx.net>

BUGS/FEEDBACK
Please send any comments, questions, bug reports etc. to me by e-mail or register them at sourceforge project home. Feature requests are also welcomed.

HOME
<http://sourceforge.net/projects/runawk/>

SEE ALSO awk(1)