AWK is a line-oriented language. The pattern comes first, and
then the action. Action statements are enclosed in { and }.
Either the pattern may be missing, or the action may be missing,
but, of course, not both. If the pattern is missing, the action
executes for every single record of input. A missing action is
equivalent to
{ print }
which prints the entire record.
Comments begin with the # character, and continue until the end
of the line. Empty lines may be used to separate statements.
Normally, a statement ends with a newline, however, this is not
the case for lines ending in a comma, {, ?, :, &&, or ||. Lines
ending in do or else also have their statements automatically
continued on the following line. In other cases, a line can be
continued by ending it with a '\', in which case the newline is
ignored. However, a '\' after a # is not special.
Multiple statements may be put on one line by separating them
with a ';'. This applies to both the statements within the
action part of a pattern-action pair (the usual case), and to the
pattern-action statements themselves.
Patterns
AWK patterns may be one of the following:
BEGIN
END
BEGINFILE
ENDFILE
/regular expression/
relational expression
pattern && pattern
pattern || pattern
pattern ? pattern : pattern
(pattern)
! pattern
pattern1, pattern2
BEGIN and END are two special kinds of patterns which are not
tested against the input. The action parts of all BEGIN patterns
are merged as if all the statements had been written in a single
BEGIN rule. They are executed before any of the input is read.
Similarly, all the END rules are merged, and executed when all
the input is exhausted (or when an exit statement is executed).
BEGIN and END patterns cannot be combined with other patterns in
pattern expressions. BEGIN and END patterns cannot have missing
action parts.
BEGINFILE and ENDFILE are additional special patterns whose
actions are executed before reading the first record of each
command-line input file and after reading the last record of each
file. Inside the BEGINFILE rule, the value of ERRNO is the empty
string if the file was opened successfully. Otherwise, there is
some problem with the file and the code should use nextfile to
skip it. If that is not done, gawk produces its usual fatal error
for files that cannot be opened.
For /regular expression/ patterns, the associated statement is
executed for each input record that matches the regular
expression. Regular expressions are the same as those in
egrep(1), and are summarized below.
A relational expression may use any of the operators defined
below in the section on actions. These generally test whether
certain fields match certain regular expressions.
The &&, ||, and ! operators are logical AND, logical OR, and
logical NOT, respectively, as in C. They do short-circuit
evaluation, also as in C, and are used for combining more
primitive pattern expressions. As in most languages, parentheses
may be used to change the order of evaluation.
The ?: operator is like the same operator in C. If the first
pattern is true then the pattern used for testing is the second
pattern, otherwise it is the third. Only one of the second and
third patterns is evaluated.
The pattern1, pattern2 form of an expression is called a range
pattern. It matches all input records starting with a record
that matches pattern1, and continuing until a record that matches
pattern2, inclusive. It does not combine with any other sort of
pattern expression.
Regular Expressions
Regular expressions are the extended kind found in egrep. They
are composed of characters as follows:
c Matches the non-metacharacter c.
\c Matches the literal character c.
. Matches any character including newline.
^ Matches the beginning of a string.
$ Matches the end of a string.
[abc...]
A character list: matches any of the characters abc....
You may include a range of characters by separating them
with a dash. To include a literal dash in the list, put
it first or last.
[^abc...]
A negated character list: matches any character except
abc....
r1|r2 Alternation: matches either r1 or r2.
r1r2 Concatenation: matches r1, and then r2.
r+ Matches one or more r's.
r* Matches zero or more r's.
r? Matches zero or one r's.
(r) Grouping: matches r.
r{n}
r{n,}
r{n,m} One or two numbers inside braces denote an interval
expression. If there is one number in the braces, the
preceding regular expression r is repeated n times. If
there are two numbers separated by a comma, r is repeated
n to m times. If there is one number followed by a comma,
then r is repeated at least n times.
\y Matches the empty string at either the beginning or the
end of a word.
\B Matches the empty string within a word.
\< Matches the empty string at the beginning of a word.
\> Matches the empty string at the end of a word.
\s Matches any whitespace character.
\S Matches any nonwhitespace character.
\w Matches any word-constituent character (letter, digit, or
underscore).
\W Matches any character that is not word-constituent.
\` Matches the empty string at the beginning of a buffer
(string).
\' Matches the empty string at the end of a buffer.
The escape sequences that are valid in string constants (see
String Constants) are also valid in regular expressions.
Character classes are a feature introduced in the POSIX standard.
A character class is a special notation for describing lists of
characters that have a specific attribute, but where the actual
characters themselves can vary from country to country and/or
from character set to character set. For example, the notion of
what is an alphabetic character differs in the USA and in France.
A character class is only valid in a regular expression inside
the brackets of a character list. Character classes consist of
[:, a keyword denoting the class, and :]. The character classes
defined by the POSIX standard are:
[:alnum:]
Alphanumeric characters.
[:alpha:]
Alphabetic characters.
[:blank:]
Space or tab characters.
[:cntrl:]
Control characters.
[:digit:]
Numeric characters.
[:graph:]
Characters that are both printable and visible. (A space
is printable, but not visible, while an a is both.)
[:lower:]
Lowercase alphabetic characters.
[:print:]
Printable characters (characters that are not control
characters.)
[:punct:]
Punctuation characters (characters that are not letter,
digits, control characters, or space characters).
[:space:]
Space characters (such as space, tab, and formfeed, to
name a few).
[:upper:]
Uppercase alphabetic characters.
[:xdigit:]
Characters that are hexadecimal digits.
For example, before the POSIX standard, to match alphanumeric
characters, you would have had to write /[A-Za-z0-9]/. If your
character set had other alphabetic characters in it, this would
not match them, and if your character set collated differently
from ASCII, this might not even match the ASCII alphanumeric
characters. With the POSIX character classes, you can write
/[[:alnum:]]/, and this matches the alphabetic and numeric
characters in your character set, no matter what it is.
Two additional special sequences can appear in character lists.
These apply to non-ASCII character sets, which can have single
symbols (called collating elements) that are represented with
more than one character, as well as several characters that are
equivalent for collating, or sorting, purposes. (E.g., in
French, a plain 'e' and a grave-accented 'e`' are equivalent.)
Collating Symbols
A collating symbol is a multi-character collating element
enclosed in [. and .]. For example, if ch is a collating
element, then [[.ch.]] is a regular expression that
matches this collating element, while [ch] is a regular
expression that matches either c or h.
Equivalence Classes
An equivalence class is a locale-specific name for a list
of characters that are equivalent. The name is enclosed
in [= and =]. For example, the name e might be used to
represent all of 'e', 'e´', and 'e`'. In this case, [[=e=]]
is a regular expression that matches any of e, e´, or e`.
These features are very valuable in non-English speaking locales.
The library functions that gawk uses for regular expression
matching currently only recognize POSIX character classes; they
do not recognize collating symbols or equivalence classes.
The \y, \B, \<, \>, \s, \S, \w, \W, \`, and \' operators are
specific to gawk; they are extensions based on facilities in the
GNU regular expression libraries.
The various command line options control how gawk interprets
characters in regular expressions.
No options
In the default case, gawk provides all the facilities of
POSIX regular expressions and the GNU regular expression
operators described above.
--posix
Only POSIX regular expressions are supported, the GNU
operators are not special. (E.g., \w matches a literal
w).
--traditional
Traditional UNIX awk regular expressions are matched. The
GNU operators are not special, and interval expressions
are not available. Characters described by octal and
hexadecimal escape sequences are treated literally, even
if they represent regular expression metacharacters.
--re-interval
Allow interval expressions in regular expressions, even if
--traditional has been provided.
Actions
Action statements are enclosed in braces, { and }. Action
statements consist of the usual assignment, conditional, and
looping statements found in most languages. The operators,
control statements, and input/output statements available are
patterned after those in C.
Operators
The operators in AWK, in order of decreasing precedence, are:
(...) Grouping
$ Field reference.
++ -- Increment and decrement, both prefix and postfix.
^ Exponentiation (** may also be used, and **= for the
assignment operator).
+ - ! Unary plus, unary minus, and logical negation.
* / % Multiplication, division, and modulus.
+ - Addition and subtraction.
space String concatenation.
| |& Piped I/O for getline, print, and printf.
< > <= >= == !=
The regular relational operators.
~ !~ Regular expression match, negated match. NOTE: Do not use
a constant regular expression (/foo/) on the left-hand
side of a ~ or !~. Only use one on the right-hand side.
The expression /foo/ ~ exp has the same meaning as (($0 ~
/foo/) ~ exp). This is usually not what you want.
in Array membership.
&& Logical AND.
|| Logical OR.
?: The C conditional expression. This has the form expr1 ?
expr2 : expr3. If expr1 is true, the value of the
expression is expr2, otherwise it is expr3. Only one of
expr2 and expr3 is evaluated.
= += -= *= /= %= ^=
Assignment. Both absolute assignment (var = value) and
operator-assignment (the other forms) are supported.
Control Statements
The control statements are as follows:
if (condition) statement [ else statement ]
while (condition) statement
do statement while (condition)
for (expr1; expr2; expr3) statement
for (var in array) statement
break
continue
delete array[index]
delete array
exit [ expression ]
{ statements }
switch (expression) {
case value|regex : statement
...
[ default: statement ]
}
I/O Statements
The input/output statements are as follows:
close(file [, how])
Close file, pipe or coprocess. The optional how should
only be used when closing one end of a two-way pipe to a
coprocess. It must be a string value, either "to" or
"from".
getline
Set $0 from the next input record; set NF, NR, FNR, RT.
getline <file
Set $0 from the next record of file; set NF, RT.
getline var
Set var from the next input record; set NR, FNR, RT.
getline var <file
Set var from the next record of file; set RT.
command | getline [var]
Run command, piping the output either into $0 or var, as
above, and RT.
command |& getline [var]
Run command as a coprocess piping the output either into
$0 or var, as above, and RT. Coprocesses are a gawk
extension. (The command can also be a socket. See the
subsection Special File Names, below.)
next Stop processing the current input record. Read the next
input record and start processing over with the first
pattern in the AWK program. Upon reaching the end of the
input data, execute any END rule(s).
nextfile
Stop processing the current input file. The next input
record read comes from the next input file. Update
FILENAME and ARGIND, reset FNR to 1, and start processing
over with the first pattern in the AWK program. Upon
reaching the end of the input data, execute any ENDFILE
and END rule(s).
print Print the current record. The output record is terminated
with the value of ORS.
print expr-list
Print expressions. Each expression is separated by the
value of OFS. The output record is terminated with the
value of ORS.
print expr-list >file
Print expressions on file. Each expression is separated
by the value of OFS. The output record is terminated with
the value of ORS.
printf fmt, expr-list
Format and print. See The printf Statement, below.
printf fmt, expr-list >file
Format and print on file.
system(cmd-line)
Execute the command cmd-line, and return the exit status.
(This may not be available on non-POSIX systems.) See
GAWK: Effective AWK Programming for the full details on
the exit status.
fflush([file])
Flush any buffers associated with the open output file or
pipe file. If file is missing or if it is the null
string, then flush all open output files and pipes.
Additional output redirections are allowed for print and printf.
print ... >> file
Append output to the file.
print ... | command
Write on a pipe.
print ... |& command
Send data to a coprocess or socket. (See also the
subsection Special File Names, below.)
The getline command returns 1 on success, zero on end of file,
and -1 on an error. If the errno(3) value indicates that the I/O
operation may be retried, and PROCINFO["input", "RETRY"] is set,
then -2 is returned instead of -1, and further calls to getline
may be attempted. Upon an error, ERRNO is set to a string
describing the problem.
NOTE: Failure in opening a two-way socket results in a non-fatal
error being returned to the calling function. If using a pipe,
coprocess, or socket to getline, or from print or printf within a
loop, you must use close() to create new instances of the command
or socket. AWK does not automatically close pipes, sockets, or
coprocesses when they return EOF.
The printf Statement
The AWK versions of the printf statement and sprintf() function
(see below) accept the following conversion specification
formats:
%a, %A A floating point number of the form [-]0xh.hhhhp+-dd (C99
hexadecimal floating point format). For %A, uppercase
letters are used instead of lowercase ones.
%c A single character. If the argument used for %c is
numeric, it is treated as a character and printed.
Otherwise, the argument is assumed to be a string, and the
only first character of that string is printed.
%d, %i A decimal number (the integer part).
%e, %E A floating point number of the form [-]d.dddddde[+-]dd.
The %E format uses E instead of e.
%f, %F A floating point number of the form [-]ddd.dddddd. If the
system library supports it, %F is available as well. This
is like %f, but uses capital letters for special 'not a
number' and 'infinity' values. If %F is not available,
gawk uses %f.
%g, %G Use %e or %f conversion, whichever is shorter, with
nonsignificant zeros suppressed. The %G format uses %E
instead of %e.
%o An unsigned octal number (also an integer).
%u An unsigned decimal number (again, an integer).
%s A character string.
%x, %X An unsigned hexadecimal number (an integer). The %X
format uses ABCDEF instead of abcdef.
%% A single % character; no argument is converted.
Optional, additional parameters may lie between the % and the
control letter:
count$ Use the count'th argument at this point in the formatting.
This is called a positional specifier and is intended
primarily for use in translated versions of format
strings, not in the original text of an AWK program. It
is a gawk extension.
- The expression should be left-justified within its field.
space For numeric conversions, prefix positive values with a
space, and negative values with a minus sign.
+ The plus sign, used before the width modifier (see below),
says to always supply a sign for numeric conversions, even
if the data to be formatted is positive. The + overrides
the space modifier.
# Use an 'alternate form' for certain control letters. For
%o, supply a leading zero. For %x, and %X, supply a
leading 0x or 0X for a nonzero result. For %e, %E, %f and
%F, the result always contains a decimal point. For %g,
and %G, trailing zeros are not removed from the result.
0 A leading 0 (zero) acts as a flag, indicating that output
should be padded with zeroes instead of spaces. This
applies only to the numeric output formats. This flag
only has an effect when the field width is wider than the
value to be printed.
' A single quote character instructs gawk to insert the
locale's thousands-separator character into decimal
numbers, and to also use the locale's decimal point
character with floating point formats. This requires
correct locale support in the C library and in the
definition of the current locale.
width The field should be padded to this width. The field is
normally padded with spaces. With the 0 flag, it is
padded with zeroes.
.prec A number that specifies the precision to use when
printing. For the %e, %E, %f and %F, formats, this
specifies the number of digits you want printed to the
right of the decimal point. For the %g, and %G formats,
it specifies the maximum number of significant digits.
For the %d, %i, %o, %u, %x, and %X formats, it specifies
the minimum number of digits to print. For the %s format,
it specifies the maximum number of characters from the
string that should be printed.
The dynamic width and prec capabilities of the ISO C printf()
routines are supported. A * in place of either the width or prec
specifications causes their values to be taken from the argument
list to printf or sprintf(). To use a positional specifier with
a dynamic width or precision, supply the count$ after the * in
the format string. For example, "%3$*2$.*1$s".
Special File Names
When doing I/O redirection from either print or printf into a
file, or via getline from a file, gawk recognizes certain special
filenames internally. These filenames allow access to open file
descriptors inherited from gawk's parent process (usually the
shell). These file names may also be used on the command line to
name data files. The filenames are:
- The standard input.
/dev/stdin
The standard input.
/dev/stdout
The standard output.
/dev/stderr
The standard error output.
/dev/fd/n
The file associated with the open file descriptor n.
These are particularly useful for error messages. For example:
print "You blew it!" > "/dev/stderr"
whereas you would otherwise have to use
print "You blew it!" | "cat 1>&2"
The following special filenames may be used with the |& coprocess
operator for creating TCP/IP network connections:
/inet/tcp/lport/rhost/rport
/inet4/tcp/lport/rhost/rport
/inet6/tcp/lport/rhost/rport
Files for a TCP/IP connection on local port lport to
remote host rhost on remote port rport. Use a port of 0
to have the system pick a port. Use /inet4 to force an
IPv4 connection, and /inet6 to force an IPv6 connection.
Plain /inet uses the system default (most likely IPv4).
Usable only with the |& two-way I/O operator.
/inet/udp/lport/rhost/rport
/inet4/udp/lport/rhost/rport
/inet6/udp/lport/rhost/rport
Similar, but use UDP/IP instead of TCP/IP.
Numeric Functions
AWK has the following built-in arithmetic functions:
atan2(y, x)
Return the arctangent of y/x in radians.
cos(expr)
Return the cosine of expr, which is in radians.
exp(expr)
The exponential function.
int(expr)
Truncate to integer.
log(expr)
The natural logarithm function.
rand() Return a random number N, between zero and one, such that
0 ≤ N < 1.
sin(expr)
Return the sine of expr, which is in radians.
sqrt(expr)
Return the square root of expr.
srand([expr])
Use expr as the new seed for the random number generator.
If no expr is provided, use the time of day. Return the
previous seed for the random number generator.
String Functions
Gawk has the following built-in string functions:
asort(s [, d [, how] ])
Return the number of elements in the source array s. Sort
the contents of s using gawk's normal rules for comparing
values, and replace the indices of the sorted values s
with sequential integers starting with 1. If the optional
destination array d is specified, first duplicate s into
d, and then sort d, leaving the indices of the source
array s unchanged. The optional string how controls the
direction and the comparison mode. Valid values for how
are any of the strings valid for PROCINFO["sorted_in"].
It can also be the name of a user-defined comparison
function as described in PROCINFO["sorted_in"]. s and d
are allowed to be the same array; this only makes sense
when supplying the third argument as well.
asorti(s [, d [, how] ])
Return the number of elements in the source array s. The
behavior is the same as that of asort(), except that the
array indices are used for sorting, not the array values.
When done, the array is indexed numerically, and the
values are those of the original indices. The original
values are lost; thus provide a second array if you wish
to preserve the original. The purpose of the optional
string how is the same as described previously for
asort(). Here too, s and d are allowed to be the same
array; this only makes sense when supplying the third
argument as well.
gensub(r, s, h [, t])
Search the target string t for matches of the regular
expression r. If h is a string beginning with g or G,
then replace all matches of r with s. Otherwise, h is a
number indicating which match of r to replace. If t is
not supplied, use $0 instead. Within the replacement text
s, the sequence \n, where n is a digit from 1 to 9, may be
used to indicate just the text that matched the n'th
parenthesized subexpression. The sequence \0 represents
the entire matched text, as does the character &. Unlike
sub() and gsub(), the modified string is returned as the
result of the function, and the original target string is
not changed.
gsub(r, s [, t])
For each substring matching the regular expression r in
the string t, substitute the string s, and return the
number of substitutions. If t is not supplied, use $0.
An & in the replacement text is replaced with the text
that was actually matched. Use \& to get a literal &.
(This must be typed as "\\&"; see GAWK: Effective AWK
Programming for a fuller discussion of the rules for
ampersands and backslashes in the replacement text of
sub(), gsub(), and gensub().)
index(s, t)
Return the index of the string t in the string s, or zero
if t is not present. (This implies that character indices
start at one.) It is a fatal error to use a regexp
constant for t.
length([s])
Return the length of the string s, or the length of $0 if
s is not supplied. As a non-standard extension, with an
array argument, length() returns the number of elements in
the array.
match(s, r [, a])
Return the position in s where the regular expression r
occurs, or zero if r is not present, and set the values of
RSTART and RLENGTH. Note that the argument order is the
same as for the ~ operator: str ~ re. If array a is
provided, a is cleared and then elements 1 through n are
filled with the portions of s that match the corresponding
parenthesized subexpression in r. The zero'th element of
a contains the portion of s matched by the entire regular
expression r. Subscripts a[n, "start"], and a[n,
"length"] provide the starting index in the string and
length respectively, of each matching substring.
patsplit(s, a [, r [, seps] ])
Split the string s into the array a and the separators
array seps on the regular expression r, and return the
number of fields. Element values are the portions of s
that matched r. The value of seps[i] is the possibly null
separator that appeared after a[i]. The value of seps[0]
is the possibly null leading separator. If r is omitted,
FPAT is used instead. The arrays a and seps are cleared
first. Splitting behaves identically to field splitting
with FPAT, described above.
split(s, a [, r [, seps] ])
Split the string s into the array a and the separators
array seps on the regular expression r, and return the
number of fields. If r is omitted, FS is used instead.
The arrays a and seps are cleared first. seps[i] is the
field separator matched by r between a[i] and a[i+1]. If
r is a single space, then leading whitespace in s goes
into the extra array element seps[0] and trailing
whitespace goes into the extra array element seps[n],
where n is the return value of split(s, a, r, seps).
Splitting behaves identically to field splitting,
described above. In particular, if r is a single-
character string, that string acts as the separator, even
if it happens to be a regular expression metacharacter.
sprintf(fmt, expr-list)
Print expr-list according to fmt, and return the resulting
string.
strtonum(str)
Examine str, and return its numeric value. If str begins
with a leading 0, treat it as an octal number. If str
begins with a leading 0x or 0X, treat it as a hexadecimal
number. Otherwise, assume it is a decimal number.
sub(r, s [, t])
Just like gsub(), but replace only the first matching
substring. Return either zero or one.
substr(s, i [, n])
Return the at most n-character substring of s starting at
i. If n is omitted, use the rest of s.
tolower(str)
Return a copy of the string str, with all the uppercase
characters in str translated to their corresponding
lowercase counterparts. Non-alphabetic characters are
left unchanged.
toupper(str)
Return a copy of the string str, with all the lowercase
characters in str translated to their corresponding
uppercase counterparts. Non-alphabetic characters are
left unchanged.
Gawk is multibyte aware. This means that index(), length(),
substr() and match() all work in terms of characters, not bytes.
Time Functions
Since one of the primary uses of AWK programs is processing log
files that contain time stamp information, gawk provides the
following functions for obtaining time stamps and formatting
them.
mktime(datespec [, utc-flag])
Turn datespec into a time stamp of the same form as
returned by systime(), and return the result. The
datespec is a string of the form YYYY MM DD HH MM SS[
DST]. The contents of the string are six or seven numbers
representing respectively the full year including century,
the month from 1 to 12, the day of the month from 1 to 31,
the hour of the day from 0 to 23, the minute from 0 to 59,
the second from 0 to 60, and an optional daylight saving
flag. The values of these numbers need not be within the
ranges specified; for example, an hour of -1 means 1 hour
before midnight. The origin-zero Gregorian calendar is
assumed, with year 0 preceding year 1 and year -1
preceding year 0. If utc-flag is present and is non-zero
or non-null, the time is assumed to be in the UTC time
zone; otherwise, the time is assumed to be in the local
time zone. If the DST daylight saving flag is positive,
the time is assumed to be daylight saving time; if zero,
the time is assumed to be standard time; and if negative
(the default), mktime() attempts to determine whether
daylight saving time is in effect for the specified time.
If datespec does not contain enough elements or if the
resulting time is out of range, mktime() returns -1.
strftime([format [, timestamp[, utc-flag]]])
Format timestamp according to the specification in format.
If utc-flag is present and is non-zero or non-null, the
result is in UTC, otherwise the result is in local time.
The timestamp should be of the same form as returned by
systime(). If timestamp is missing, the current time of
day is used. If format is missing, a default format
equivalent to the output of date(1) is used. The default
format is available in PROCINFO["strftime"]. See the
specification for the strftime() function in ISO C for the
format conversions that are guaranteed to be available.
systime()
Return the current time of day as the number of seconds
since the Epoch (1970-01-01 00:00:00 UTC on POSIX
systems).
Bit Manipulations Functions
Gawk supplies the following bit manipulation functions. They
work by converting double-precision floating point values to
uintmax_t integers, doing the operation, and then converting the
result back to floating point.
NOTE: Passing negative operands to any of these functions causes
a fatal error.
The functions are:
and(v1, v2 [, ...])
Return the bitwise AND of the values provided in the
argument list. There must be at least two.
compl(val)
Return the bitwise complement of val.
lshift(val, count)
Return the value of val, shifted left by count bits.
or(v1, v2 [, ...])
Return the bitwise OR of the values provided in the
argument list. There must be at least two.
rshift(val, count)
Return the value of val, shifted right by count bits.
xor(v1, v2 [, ...])
Return the bitwise XOR of the values provided in the
argument list. There must be at least two.
Type Functions
The following functions provide type related information about
their arguments.
isarray(x)
Return true if x is an array, false otherwise. This
function is mainly for use with the elements of
multidimensional arrays and with function parameters.
typeof(x)
Return a string indicating the type of x. The string will
be one of "array", "number", "regexp", "string", "strnum",
"unassigned", or "undefined".
Internationalization Functions
The following functions may be used from within your AWK program
for translating strings at run-time. For full details, see GAWK:
Effective AWK Programming.
bindtextdomain(directory [, domain])
Specify the directory where gawk looks for the .gmo files,
in case they will not or cannot be placed in the
``standard'' locations (e.g., during testing). It returns
the directory where domain is ``bound.''
The default domain is the value of TEXTDOMAIN. If
directory is the null string (""), then bindtextdomain()
returns the current binding for the given domain.
dcgettext(string [, domain [, category]])
Return the translation of string in text domain domain for
locale category category. The default value for domain is
the current value of TEXTDOMAIN. The default value for
category is "LC_MESSAGES".
If you supply a value for category, it must be a string
equal to one of the known locale categories described in
GAWK: Effective AWK Programming. You must also supply a
text domain. Use TEXTDOMAIN if you want to use the
current domain.
dcngettext(string1, string2, number [, domain [, category]])
Return the plural form used for number of the translation
of string1 and string2 in text domain domain for locale
category category. The default value for domain is the
current value of TEXTDOMAIN. The default value for
category is "LC_MESSAGES".
If you supply a value for category, it must be a string
equal to one of the known locale categories described in
GAWK: Effective AWK Programming. You must also supply a
text domain. Use TEXTDOMAIN if you want to use the
current domain.
Boolean Valued Functions
You can create special Boolean-typed values; see the manual for
how they work and why they exist.
mkbool(expression)
Based on the boolean value of expression return either a
true value or a false value. True values have numeric
value one. False values have numeric value zero.
