man/man1/awk.1 - plan9 - Git at Google

 .TH AWK 1
 .SH NAME
 awk \- pattern-directed scanning and processing language
 .SH SYNOPSIS
 .B awk
 [
 .B -F
 .I fs
 ]
 [
 .B -d
 ]
 [
 .BI -mf
 .I n
 ]
 [
 .B -mr
 .I n
 ]
 [
 .B -safe
 ]
 [
 .B -v
 .I var=value
 ]
 [
 .B -f
 .I progfile
 |
 .I prog
 ]
 [
 .I file ...
 ]
 .SH DESCRIPTION
 .I Awk
 scans each input
 .I file
 for lines that match any of a set of patterns specified literally in
 .I prog
 or in one or more files
 specified as
 .B -f
 .IR progfile .
 With each pattern
 there can be an associated action that will be performed
 when a line of a
 .I file
 matches the pattern.
 Each line is matched against the
 pattern portion of every pattern-action statement;
 the associated action is performed for each matched pattern.
 The file name
 .L -
 means the standard input.
 Any
 .IR file
 of the form
 .I var=value
 is treated as an assignment, not a file name,
 and is executed at the time it would have been opened if it were a file name.
 The option
 .B -v
 followed by
 .I var=value
 is an assignment to be done before the program
 is executed;
 any number of
 .B -v
 options may be present.
 .B -F
 .IR fs
 option defines the input field separator to be the regular expression
 .IR fs .
 .PP
 An input line is normally made up of fields separated by white space,
 or by regular expression
 .BR FS .
 The fields are denoted
 .BR $1 ,
 .BR $2 ,
 \&..., while
 .B $0
 refers to the entire line.
 If
 .BR FS
 is null, the input line is split into one field per character.
 .PP
 To compensate for inadequate implementation of storage management,
 the
 .B -mr
 option can be used to set the maximum size of the input record,
 and the
 .B -mf
 option to set the maximum number of fields.
 .PP
 The
 .B -safe
 option causes
 .I awk
 to run in
 ``safe mode,''
 in which it is not allowed to
 run shell commands or open files
 and the environment is not made available
 in the
 .B ENVIRON
 variable.
 .PP
 A pattern-action statement has the form
 .IP
 .IB pattern " { " action " }
 .PP
 A missing
 .BI { " action " }
 means print the line;
 a missing pattern always matches.
 Pattern-action statements are separated by newlines or semicolons.
 .PP
 An action is a sequence of statements.
 A statement can be one of the following:
 .PP
 .EX
 .ta \w'\fLdelete array[expression]'u
 if(\fI expression \fP)\fI statement \fP\fR[ \fPelse\fI statement \fP\fR]\fP
 while(\fI expression \fP)\fI statement\fP
 for(\fI expression \fP;\fI expression \fP;\fI expression \fP)\fI statement\fP
 for(\fI var \fPin\fI array \fP)\fI statement\fP
 do\fI statement \fPwhile(\fI expression \fP)
 break
 continue
 {\fR [\fP\fI statement ... \fP\fR] \fP}
 \fIexpression\fP	#\fR commonly\fP\fI var = expression\fP
 print\fR [ \fP\fIexpression-list \fP\fR] \fP\fR[ \fP>\fI expression \fP\fR]\fP
 printf\fI format \fP\fR[ \fP,\fI expression-list \fP\fR] \fP\fR[ \fP>\fI expression \fP\fR]\fP
 return\fR [ \fP\fIexpression \fP\fR]\fP
 next	#\fR skip remaining patterns on this input line\fP
 nextfile	#\fR skip rest of this file, open next, start at top\fP
 delete\fI array\fP[\fI expression \fP]	#\fR delete an array element\fP
 delete\fI array\fP	#\fR delete all elements of array\fP
 exit\fR [ \fP\fIexpression \fP\fR]\fP	#\fR exit immediately; status is \fP\fIexpression\fP
 .EE
 .DT
 .PP
 Statements are terminated by
 semicolons, newlines or right braces.
 An empty
 .I expression-list
 stands for
 .BR $0 .
 String constants are quoted \&\fL"\ "\fR,
 with the usual C escapes recognized within.
 Expressions take on string or numeric values as appropriate,
 and are built using the operators
 .B + \- * / % ^
 (exponentiation), and concatenation (indicated by white space).
 The operators
 .B
 ! ++ \-\- += \-= *= /= %= ^= > >= < <= == != ?:
 are also available in expressions.
 Variables may be scalars, array elements
 (denoted
 .IB x  [ i ] )
 or fields.
 Variables are initialized to the null string.
 Array subscripts may be any string,
 not necessarily numeric;
 this allows for a form of associative memory.
 Multiple subscripts such as
 .B [i,j,k]
 are permitted; the constituents are concatenated,
 separated by the value of
 .BR SUBSEP .
 .PP
 The
 .B print
 statement prints its arguments on the standard output
 (or on a file if
 .BI > file
 or
 .BI >> file
 is present or on a pipe if
 .BI | cmd
 is present), separated by the current output field separator,
 and terminated by the output record separator.
 .I file
 and
 .I cmd
 may be literal names or parenthesized expressions;
 identical string values in different statements denote
 the same open file.
 The
 .B printf
 statement formats its expression list according to the format
 (see
 .IR fprintf (3)) .
 The built-in function
 .BI close( expr )
 closes the file or pipe
 .IR expr .
 The built-in function
 .BI fflush( expr )
 flushes any buffered output for the file or pipe
 .IR expr .
 If
 .IR expr
 is omitted or is a null string, all open files are flushed.
 .PP
 The mathematical functions
 .BR exp ,
 .BR log ,
 .BR sqrt ,
 .BR sin ,
 .BR cos ,
 and
 .BR atan2
 are built in.
 Other built-in functions:
 .TF length
 .TP
 .B length
 If its argument is a string, the string's length is returned.
 If its argument is an array, the number of subscripts in the array is returned.
 If no argument, the length of
 .B $0
 is returned.
 .TP
 .B rand
 random number on (0,1)
 .TP
 .B srand
 sets seed for
 .B rand
 and returns the previous seed.
 .TP
 .B int
 truncates to an integer value
 .TP
 .B utf
 converts its numerical argument, a character number, to a
 .SM UTF
 string
 .TP
 .BI substr( s , " m" , " n\fL)
 the
 .IR n -character
 substring of
 .I s
 that begins at position
 .IR m
 counted from 1.
 .TP
 .BI index( s , " t" )
 the position in
 .I s
 where the string
 .I t
 occurs, or 0 if it does not.
 .TP
 .BI match( s , " r" )
 the position in
 .I s
 where the regular expression
 .I r
 occurs, or 0 if it does not.
 The variables
 .B RSTART
 and
 .B RLENGTH
 are set to the position and length of the matched string.
 .TP
 .BI split( s , " a" , " fs\fL)
 splits the string
 .I s
 into array elements
 .IB a [1]\f1,
 .IB a [2]\f1,
 \&...,
 .IB a [ n ]\f1,
 and returns
 .IR n .
 The separation is done with the regular expression
 .I fs
 or with the field separator
 .B FS
 if
 .I fs
 is not given.
 An empty string as field separator splits the string
 into one array element per character.
 .TP
 .BI sub( r , " t" , " s\fL)
 substitutes
 .I t
 for the first occurrence of the regular expression
 .I r
 in the string
 .IR s .
 If
 .I s
 is not given,
 .B $0
 is used.
 .TP
 .B gsub
 same as
 .B sub
 except that all occurrences of the regular expression
 are replaced;
 .B sub
 and
 .B gsub
 return the number of replacements.
 .TP
 .BI sprintf( fmt , " expr" , " ...\fL)
 the string resulting from formatting
 .I expr ...
 according to the
 .I printf
 format
 .I fmt
 .TP
 .BI system( cmd )
 executes
 .I cmd
 and returns its exit status
 .TP
 .BI tolower( str )
 returns a copy of
 .I str
 with all upper-case characters translated to their
 corresponding lower-case equivalents.
 .TP
 .BI toupper( str )
 returns a copy of
 .I str
 with all lower-case characters translated to their
 corresponding upper-case equivalents.
 .PD
 .PP
 The ``function''
 .B getline
 sets
 .B $0
 to the next input record from the current input file;
 .B getline
 .BI < file
 sets
 .B $0
 to the next record from
 .IR file .
 .B getline
 .I x
 sets variable
 .I x
 instead.
 Finally,
 .IB cmd " | getline
 pipes the output of
 .I cmd
 into
 .BR getline ;
 each call of
 .B getline
 returns the next line of output from
 .IR cmd .
 In all cases,
 .B getline
 returns 1 for a successful input,
 0 for end of file, and \-1 for an error.
 .PP
 Patterns are arbitrary Boolean combinations
 (with
 .BR "! || &&" )
 of regular expressions and
 relational expressions.
 Regular expressions are as in
 .IR regexp (7).
 Isolated regular expressions
 in a pattern apply to the entire line.
 Regular expressions may also occur in
 relational expressions, using the operators
 .BR ~
 and
 .BR !~ .
 .BI / re /
 is a constant regular expression;
 any string (constant or variable) may be used
 as a regular expression, except in the position of an isolated regular expression
 in a pattern.
 .PP
 A pattern may consist of two patterns separated by a comma;
 in this case, the action is performed for all lines
 from an occurrence of the first pattern
 though an occurrence of the second.
 .PP
 A relational expression is one of the following:
 .IP
 .I expression matchop regular-expression
 .br
 .I expression relop expression
 .br
 .IB expression " in " array-name
 .br
 .BI ( expr , expr,... ") in " array-name
 .PP
 where a
 .I relop
 is any of the six relational operators in C,
 and a
 .I matchop
 is either
 .B ~
 (matches)
 or
 .B !~
 (does not match).
 A conditional is an arithmetic expression,
 a relational expression,
 or a Boolean combination
 of these.
 .PP
 The special patterns
 .B BEGIN
 and
 .B END
 may be used to capture control before the first input line is read
 and after the last.
 .B BEGIN
 and
 .B END
 do not combine with other patterns.
 .PP
 Variable names with special meanings:
 .TF FILENAME
 .TP
 .B CONVFMT
 conversion format used when converting numbers
 (default
 .BR "%.6g" )
 .TP
 .B FS
 regular expression used to separate fields; also settable
 by option
 .BI \-F fs\f1.
 .TP
 .BR NF
 number of fields in the current record
 .TP
 .B NR
 ordinal number of the current record
 .TP
 .B FNR
 ordinal number of the current record in the current file
 .TP
 .B FILENAME
 the name of the current input file
 .TP
 .B RS
 input record separator (default newline)
 .TP
 .B OFS
 output field separator (default blank)
 .TP
 .B ORS
 output record separator (default newline)
 .TP
 .B OFMT
 output format for numbers (default
 .BR "%.6g" )
 .TP
 .B SUBSEP
 separates multiple subscripts (default 034)
 .TP
 .B ARGC
 argument count, assignable
 .TP
 .B ARGV
 argument array, assignable;
 non-null members are taken as file names
 .TP
 .B ENVIRON
 array of environment variables; subscripts are names.
 .PD
 .PP
 Functions may be defined (at the position of a pattern-action statement) thus:
 .IP
 .L
 function foo(a, b, c) { ...; return x }
 .PP
 Parameters are passed by value if scalar and by reference if array name;
 functions may be called recursively.
 Parameters are local to the function; all other variables are global.
 Thus local variables may be created by providing excess parameters in
 the function definition.
 .SH EXAMPLES
 .TP
 .L
 length($0) > 72
 Print lines longer than 72 characters.
 .TP
 .L
 { print $2, $1 }
 Print first two fields in opposite order.
 .PP
 .EX
 BEGIN { FS = ",[ \et]*|[ \et]+" }
       { print $2, $1 }
 .EE
 .ns
 .IP
 Same, with input fields separated by comma and/or blanks and tabs.
 .PP
 .EX
 	{ s += $1 }
 END	{ print "sum is", s, " average is", s/NR }
 .EE
 .ns
 .IP
 Add up first column, print sum and average.
 .TP
 .L
 /start/, /stop/
 Print all lines between start/stop pairs.
 .PP
 .EX
 BEGIN	{	# Simulate echo(1)
 	for (i = 1; i < ARGC; i++) printf "%s ", ARGV[i]
 	printf "\en"
 	exit }
 .EE
 .SH SOURCE
 .B \*9/src/cmd/awk
 .SH SEE ALSO
 .IR sed (1),
 .IR regexp (7),
 .br
 A. V. Aho, B. W. Kernighan, P. J. Weinberger,
 .I
 The AWK Programming Language,
 Addison-Wesley, 1988.  ISBN 0-201-07981-X
 .SH BUGS
 There are no explicit conversions between numbers and strings.
 To force an expression to be treated as a number add 0 to it;
 to force it to be treated as a string concatenate
 \&\fL""\fP to it.
 .br
 The scope rules for variables in functions are a botch;
 the syntax is worse.
 .br
 UTF is not always dealt with correctly,
 though
 .I awk
 does make an attempt to do so.
 The
 .I split
 function with an empty string as final argument now copes
 with UTF in the string being split.
	.TH AWK 1
	.SH NAME
	awk \- pattern-directed scanning and processing language
	.SH SYNOPSIS
	.B awk
	[
	.B -F
	.I fs
	]
	[
	.B -d
	]
	[
	.BI -mf
	.I n
	]
	[
	.B -mr
	.I n
	]
	[
	.B -safe
	]
	[
	.B -v
	.I var=value
	]
	[
	.B -f
	.I progfile
	\|
	.I prog
	]
	[
	.I file ...
	]
	.SH DESCRIPTION
	.I Awk
	scans each input
	.I file
	for lines that match any of a set of patterns specified literally in
	.I prog
	or in one or more files
	specified as
	.B -f
	.IR progfile .
	With each pattern
	there can be an associated action that will be performed
	when a line of a
	.I file
	matches the pattern.
	Each line is matched against the
	pattern portion of every pattern-action statement;
	the associated action is performed for each matched pattern.
	The file name
	.L -
	means the standard input.
	Any
	.IR file
	of the form
	.I var=value
	is treated as an assignment, not a file name,
	and is executed at the time it would have been opened if it were a file name.
	The option
	.B -v
	followed by
	.I var=value
	is an assignment to be done before the program
	is executed;
	any number of
	.B -v
	options may be present.
	.B -F
	.IR fs
	option defines the input field separator to be the regular expression
	.IR fs .
	.PP
	An input line is normally made up of fields separated by white space,
	or by regular expression
	.BR FS .
	The fields are denoted
	.BR $1 ,
	.BR $2 ,
	\&..., while
	.B $0
	refers to the entire line.
	If
	.BR FS
	is null, the input line is split into one field per character.
	.PP
	To compensate for inadequate implementation of storage management,
	the
	.B -mr
	option can be used to set the maximum size of the input record,
	and the
	.B -mf
	option to set the maximum number of fields.
	.PP
	The
	.B -safe
	option causes
	.I awk
	to run in
	``safe mode,''
	in which it is not allowed to
	run shell commands or open files
	and the environment is not made available
	in the
	.B ENVIRON
	variable.
	.PP
	A pattern-action statement has the form
	.IP
	.IB pattern " { " action " }
	.PP
	A missing
	.BI { " action " }
	means print the line;
	a missing pattern always matches.
	Pattern-action statements are separated by newlines or semicolons.
	.PP
	An action is a sequence of statements.
	A statement can be one of the following:
	.PP
	.EX
	.ta \w'\fLdelete array[expression]'u
	if(\fI expression \fP)\fI statement \fP\fR[ \fPelse\fI statement \fP\fR]\fP
	while(\fI expression \fP)\fI statement\fP
	for(\fI expression \fP;\fI expression \fP;\fI expression \fP)\fI statement\fP
	for(\fI var \fPin\fI array \fP)\fI statement\fP
	do\fI statement \fPwhile(\fI expression \fP)
	break
	continue
	{\fR [\fP\fI statement ... \fP\fR] \fP}
	\fIexpression\fP #\fR commonly\fP\fI var = expression\fP
	print\fR [ \fP\fIexpression-list \fP\fR] \fP\fR[ \fP>\fI expression \fP\fR]\fP
	printf\fI format \fP\fR[ \fP,\fI expression-list \fP\fR] \fP\fR[ \fP>\fI expression \fP\fR]\fP
	return\fR [ \fP\fIexpression \fP\fR]\fP
	next #\fR skip remaining patterns on this input line\fP
	nextfile #\fR skip rest of this file, open next, start at top\fP
	delete\fI array\fP[\fI expression \fP] #\fR delete an array element\fP
	delete\fI array\fP #\fR delete all elements of array\fP
	exit\fR [ \fP\fIexpression \fP\fR]\fP #\fR exit immediately; status is \fP\fIexpression\fP
	.EE
	.DT
	.PP
	Statements are terminated by
	semicolons, newlines or right braces.
	An empty
	.I expression-list
	stands for
	.BR $0 .
	String constants are quoted \&\fL"\ "\fR,
	with the usual C escapes recognized within.
	Expressions take on string or numeric values as appropriate,
	and are built using the operators
	.B + \- * / % ^
	(exponentiation), and concatenation (indicated by white space).
	The operators
	.B
	! ++ \-\- += \-= *= /= %= ^= > >= < <= == != ?:
	are also available in expressions.
	Variables may be scalars, array elements
	(denoted
	.IB x [ i ] )
	or fields.
	Variables are initialized to the null string.
	Array subscripts may be any string,
	not necessarily numeric;
	this allows for a form of associative memory.
	Multiple subscripts such as
	.B [i,j,k]
	are permitted; the constituents are concatenated,
	separated by the value of
	.BR SUBSEP .
	.PP
	The
	.B print
	statement prints its arguments on the standard output
	(or on a file if
	.BI > file
	or
	.BI >> file
	is present or on a pipe if
	.BI \| cmd
	is present), separated by the current output field separator,
	and terminated by the output record separator.
	.I file
	and
	.I cmd
	may be literal names or parenthesized expressions;
	identical string values in different statements denote
	the same open file.
	The
	.B printf
	statement formats its expression list according to the format
	(see
	.IR fprintf (3)) .
	The built-in function
	.BI close( expr )
	closes the file or pipe
	.IR expr .
	The built-in function
	.BI fflush( expr )
	flushes any buffered output for the file or pipe
	.IR expr .
	If
	.IR expr
	is omitted or is a null string, all open files are flushed.
	.PP
	The mathematical functions
	.BR exp ,
	.BR log ,
	.BR sqrt ,
	.BR sin ,
	.BR cos ,
	and
	.BR atan2
	are built in.
	Other built-in functions:
	.TF length
	.TP
	.B length
	If its argument is a string, the string's length is returned.
	If its argument is an array, the number of subscripts in the array is returned.
	If no argument, the length of
	.B $0
	is returned.
	.TP
	.B rand
	random number on (0,1)
	.TP
	.B srand
	sets seed for
	.B rand
	and returns the previous seed.
	.TP
	.B int
	truncates to an integer value
	.TP
	.B utf
	converts its numerical argument, a character number, to a
	.SM UTF
	string
	.TP
	.BI substr( s , " m" , " n\fL)
	the
	.IR n -character
	substring of
	.I s
	that begins at position
	.IR m
	counted from 1.
	.TP
	.BI index( s , " t" )
	the position in
	.I s
	where the string
	.I t
	occurs, or 0 if it does not.
	.TP
	.BI match( s , " r" )
	the position in
	.I s
	where the regular expression
	.I r
	occurs, or 0 if it does not.
	The variables
	.B RSTART
	and
	.B RLENGTH
	are set to the position and length of the matched string.
	.TP
	.BI split( s , " a" , " fs\fL)
	splits the string
	.I s
	into array elements
	.IB a [1]\f1,
	.IB a [2]\f1,
	\&...,
	.IB a [ n ]\f1,
	and returns
	.IR n .
	The separation is done with the regular expression
	.I fs
	or with the field separator
	.B FS
	if
	.I fs
	is not given.
	An empty string as field separator splits the string
	into one array element per character.
	.TP
	.BI sub( r , " t" , " s\fL)
	substitutes
	.I t
	for the first occurrence of the regular expression
	.I r
	in the string
	.IR s .
	If
	.I s
	is not given,
	.B $0
	is used.
	.TP
	.B gsub
	same as
	.B sub
	except that all occurrences of the regular expression
	are replaced;
	.B sub
	and
	.B gsub
	return the number of replacements.
	.TP
	.BI sprintf( fmt , " expr" , " ...\fL)
	the string resulting from formatting
	.I expr ...
	according to the
	.I printf
	format
	.I fmt
	.TP
	.BI system( cmd )
	executes
	.I cmd
	and returns its exit status
	.TP
	.BI tolower( str )
	returns a copy of
	.I str
	with all upper-case characters translated to their
	corresponding lower-case equivalents.
	.TP
	.BI toupper( str )
	returns a copy of
	.I str
	with all lower-case characters translated to their
	corresponding upper-case equivalents.
	.PD
	.PP
	The ``function''
	.B getline
	sets
	.B $0
	to the next input record from the current input file;
	.B getline
	.BI < file
	sets
	.B $0
	to the next record from
	.IR file .
	.B getline
	.I x
	sets variable
	.I x
	instead.
	Finally,
	.IB cmd " \| getline
	pipes the output of
	.I cmd
	into
	.BR getline ;
	each call of
	.B getline
	returns the next line of output from
	.IR cmd .
	In all cases,
	.B getline
	returns 1 for a successful input,
	0 for end of file, and \-1 for an error.
	.PP
	Patterns are arbitrary Boolean combinations
	(with
	.BR "! \|\| &&" )
	of regular expressions and
	relational expressions.
	Regular expressions are as in
	.IR regexp (7).
	Isolated regular expressions
	in a pattern apply to the entire line.
	Regular expressions may also occur in
	relational expressions, using the operators
	.BR ~
	and
	.BR !~ .
	.BI / re /
	is a constant regular expression;
	any string (constant or variable) may be used
	as a regular expression, except in the position of an isolated regular expression
	in a pattern.
	.PP
	A pattern may consist of two patterns separated by a comma;
	in this case, the action is performed for all lines
	from an occurrence of the first pattern
	though an occurrence of the second.
	.PP
	A relational expression is one of the following:
	.IP
	.I expression matchop regular-expression
	.br
	.I expression relop expression
	.br
	.IB expression " in " array-name
	.br
	.BI ( expr , expr,... ") in " array-name
	.PP
	where a
	.I relop
	is any of the six relational operators in C,
	and a
	.I matchop
	is either
	.B ~
	(matches)
	or
	.B !~
	(does not match).
	A conditional is an arithmetic expression,
	a relational expression,
	or a Boolean combination
	of these.
	.PP
	The special patterns
	.B BEGIN
	and
	.B END
	may be used to capture control before the first input line is read
	and after the last.
	.B BEGIN
	and
	.B END
	do not combine with other patterns.
	.PP
	Variable names with special meanings:
	.TF FILENAME
	.TP
	.B CONVFMT
	conversion format used when converting numbers
	(default
	.BR "%.6g" )
	.TP
	.B FS
	regular expression used to separate fields; also settable
	by option
	.BI \-F fs\f1.
	.TP
	.BR NF
	number of fields in the current record
	.TP
	.B NR
	ordinal number of the current record
	.TP
	.B FNR
	ordinal number of the current record in the current file
	.TP
	.B FILENAME
	the name of the current input file
	.TP
	.B RS
	input record separator (default newline)
	.TP
	.B OFS
	output field separator (default blank)
	.TP
	.B ORS
	output record separator (default newline)
	.TP
	.B OFMT
	output format for numbers (default
	.BR "%.6g" )
	.TP
	.B SUBSEP
	separates multiple subscripts (default 034)
	.TP
	.B ARGC
	argument count, assignable
	.TP
	.B ARGV
	argument array, assignable;
	non-null members are taken as file names
	.TP
	.B ENVIRON
	array of environment variables; subscripts are names.
	.PD
	.PP
	Functions may be defined (at the position of a pattern-action statement) thus:
	.IP
	.L
	function foo(a, b, c) { ...; return x }
	.PP
	Parameters are passed by value if scalar and by reference if array name;
	functions may be called recursively.
	Parameters are local to the function; all other variables are global.
	Thus local variables may be created by providing excess parameters in
	the function definition.
	.SH EXAMPLES
	.TP
	.L
	length($0) > 72
	Print lines longer than 72 characters.
	.TP
	.L
	{ print $2, $1 }
	Print first two fields in opposite order.
	.PP
	.EX
	BEGIN { FS = ",[ \et]*\|[ \et]+" }
	{ print $2, $1 }
	.EE
	.ns
	.IP
	Same, with input fields separated by comma and/or blanks and tabs.
	.PP
	.EX
	{ s += $1 }
	END { print "sum is", s, " average is", s/NR }
	.EE
	.ns
	.IP
	Add up first column, print sum and average.
	.TP
	.L
	/start/, /stop/
	Print all lines between start/stop pairs.
	.PP
	.EX
	BEGIN { # Simulate echo(1)
	for (i = 1; i < ARGC; i++) printf "%s ", ARGV[i]
	printf "\en"
	exit }
	.EE
	.SH SOURCE
	.B \*9/src/cmd/awk
	.SH SEE ALSO
	.IR sed (1),
	.IR regexp (7),
	.br
	A. V. Aho, B. W. Kernighan, P. J. Weinberger,
	.I
	The AWK Programming Language,
	Addison-Wesley, 1988. ISBN 0-201-07981-X
	.SH BUGS
	There are no explicit conversions between numbers and strings.
	To force an expression to be treated as a number add 0 to it;
	to force it to be treated as a string concatenate
	\&\fL""\fP to it.
	.br
	The scope rules for variables in functions are a botch;
	the syntax is worse.
	.br
	UTF is not always dealt with correctly,
	though
	.I awk
	does make an attempt to do so.
	The
	.I split
	function with an empty string as final argument now copes
	with UTF in the string being split.