=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/awk/awk.1,v retrieving revision 1.17 retrieving revision 1.18 diff -u -r1.17 -r1.18 --- src/usr.bin/awk/awk.1 2003/12/16 11:18:37 1.17 +++ src/usr.bin/awk/awk.1 2003/12/18 20:22:51 1.18 @@ -1,4 +1,4 @@ -.\" $OpenBSD: awk.1,v 1.17 2003/12/16 11:18:37 jmc Exp $ +.\" $OpenBSD: awk.1,v 1.18 2003/12/18 20:22:51 jmc Exp $ .\" EX/EE is a Bd .\" .\" Copyright (C) Lucent Technologies 1997 @@ -37,7 +37,7 @@ .Op Fl F Ar fs .Oo Fl v Ar var Ns = .Ns Ar value Oc -.Ar prog | Fl f Ar progfile +.Op Ar prog | Fl f Ar progfile .Ar .Nm nawk .Ar ... @@ -97,9 +97,7 @@ .Pc and access to the environment .Pf ( Va ENVIRON ; -see -.Sx VARIABLES -below). +see the section on variables below). This is a first .Pq and not very reliable approximation to a @@ -123,8 +121,20 @@ options may be present. .El .Pp +The input is normally made up of input lines +.Pq records +separated by newlines, or by the value of +.Va RS . +If +.Va RS +is null, then any number of blank lines are used as the record separator, +and newlines are used as field separators +(in addition to the value of +.Va FS ) . +This is convenient when working with multi-line records. +.Pp An input line is normally made up of fields separated by whitespace, -or by regular expression +or by the regular expression .Va FS . The fields are denoted .Va $1 , $2 , ... , @@ -135,6 +145,27 @@ .Va FS is null, the input line is split into one field per character. .Pp +Normally, any number of blanks separate fields. +In order to set the field separator to a single blank, use the +.Fl F +option with a value of +.Sq [\ \&] . +If a field separator of +.Sq t +is specified, +.Nm +treats it as if +.Sq \et +had been specified and uses +.Aq TAB +as the field separator. +In order to use a literal +.Sq t +as the field separator, use the +.Fl F +option with a value of +.Sq [t] . +.Pp A pattern-action statement has the form .Pp .D1 Ar pattern Ic \&{ Ar action Ic \&} @@ -145,6 +176,29 @@ a missing pattern always matches. Pattern-action statements are separated by newlines or semicolons. .Pp +Newlines are permitted after a terminating statement or following a comma +.Pq Sq ,\& , +an open brace +.Pq Sq { , +a logical AND +.Pq Sq && , +a logical OR +.Pq Sq || , +after the +.Sq do +or +.Sq else +keywords, +or after the closing parenthesis of an +.Sq if , +.Sq for , +or +.Sq while +statement. +Additionally, a backslash +.Pq Sq \e +can be used to escape a newline between tokens. +.Pp An action is a sequence of statements. A statement can be one of the following: .Bd -unfilled -offset indent @@ -225,9 +279,7 @@ are permitted; the constituents are concatenated, separated by the value of .Va SUBSEP -(see -.Sx VARIABLES -below). +.Pq see the section on variables below ) . .Pp The .Ic print @@ -251,6 +303,117 @@ statement formats its expression list according to the format (see .Xr printf 3 ) . +.Pp +Patterns are arbitrary Boolean combinations +(with +.Ic "\&! || &&" ) +of regular expressions and +relational expressions. +Regular expressions are as in +.Xr egrep 1 . +Isolated regular expressions +in a pattern apply to the entire line. +Regular expressions may also occur in +relational expressions, using the operators +.Ic ~ +and +.Ic !~ . +.Pf / Ns Ar re Ns / +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 +through an occurrence of the second. +.Pp +A relational expression is one of the following: +.Bd -unfilled -offset indent +.Ar expression matchop regular-expression +.Ar expression relop expression +.Ar expression Ic in Ar array-name +.Ic \&( Ns Xo +.Ar expr , expr , \&... Ns Ic \&) in +.Ar \& array-name +.Xc +.Ed +.Pp +where a +.Ar relop +is any of the six relational operators in C, and a +.Ar matchop +is either +.Ic ~ +(matches) +or +.Ic !~ +(does not match). +A conditional is an arithmetic expression, +a relational expression, +or a Boolean combination +of these. +.Pp +The special patterns +.Ic BEGIN +and +.Ic END +may be used to capture control before the first input line is read +and after the last. +.Ic BEGIN +and +.Ic END +do not combine with other patterns. +.Pp +Variable names with special meanings: +.Pp +.Bl -tag -width "FILENAME" -compact +.It Va ARGC +Argument count, assignable. +.It Va ARGV +Argument array, assignable; +non-null members are taken as filenames. +.It Va CONVFMT +Conversion format when converting numbers +(default +.Qq Li %.6g ) . +.It Va ENVIRON +Array of environment variables; subscripts are names. +.It Va FILENAME +The name of the current input file. +.It Va FNR +Ordinal number of the current record in the current file. +.It Va FS +Regular expression used to separate fields; also settable +by option +.Fl F Ar fs . +.It Va NF +Number of fields in the current record. +.Va $NF +can be used to obtain the value of the last field in the current record. +.It Va NR +Ordinal number of the current record. +.It Va OFMT +Output format for numbers (default +.Qq Li %.6g ) . +.It Va OFS +Output field separator (default blank). +.It Va ORS +Output record separator (default newline). +.It Va RLENGTH +The length of the string matched by the +.Fn match +function. +.It Va RS +Input record separator (default newline). +.It Va RSTART +The starting position of the string matched by the +.Fn match +function. +.It Va SUBSEP +Separates multiple subscripts (default 034). +.El .Sh FUNCTIONS The awk language has a variety of built-in functions: arithmetic, string, input/output and general. @@ -512,115 +675,6 @@ 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 PATTERNS -Patterns are arbitrary Boolean combinations -(with -.Ic "\&! || &&" ) -of regular expressions and -relational expressions. -Regular expressions are as in -.Xr egrep 1 . -Isolated regular expressions -in a pattern apply to the entire line. -Regular expressions may also occur in -relational expressions, using the operators -.Ic ~ -and -.Ic !~ . -.Pf / Ns Ar re Ns / -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 -through an occurrence of the second. -.Pp -A relational expression is one of the following: -.Bd -unfilled -offset indent -.Ar expression matchop regular-expression -.Ar expression relop expression -.Ar expression Ic in Ar array-name -.Ic \&( Ns Xo -.Ar expr , expr , \&... Ns Ic \&) in -.Ar \& array-name -.Xc -.Ed -.Pp -where a -.Ar relop -is any of the six relational operators in C, and a -.Ar matchop -is either -.Ic ~ -(matches) -or -.Ic !~ -(does not match). -A conditional is an arithmetic expression, -a relational expression, -or a Boolean combination -of these. -.Pp -The special patterns -.Ic BEGIN -and -.Ic END -may be used to capture control before the first input line is read -and after the last. -.Ic BEGIN -and -.Ic END -do not combine with other patterns. -.Sh VARIABLES -Variable names with special meanings: -.Pp -.Bl -tag -width "FILENAME" -compact -.It Va ARGC -Argument count, assignable. -.It Va ARGV -Argument array, assignable; -non-null members are taken as filenames. -.It Va CONVFMT -Conversion format used when converting numbers -(default -.Qq Li %.6g ) . -.It Va ENVIRON -Array of environment variables; subscripts are names. -.It Va FILENAME -The name of the current input file. -.It Va FNR -Ordinal number of the current record in the current file. -.It Va FS -Regular expression used to separate fields; also settable -by option -.Fl F Ar fs . -.It Va NF -Number of fields in the current record. -.It Va NR -Ordinal number of the current record. -.It Va OFMT -Output format for numbers (default -.Qq Li %.6g ) . -.It Va OFS -Output field separator (default blank). -.It Va ORS -Output record separator (default newline). -.It Va RLENGTH -The length of the string matched by the -.Fn match -function. -.It Va RS -Input record separator (default newline). -.It Va RSTART -The starting position of the string matched by the -.Fn match -function. -.It Va SUBSEP -Separates multiple subscripts (default 034). -.El .Sh EXAMPLES Print lines longer than 72 characters: .Pp