Annotation of src/usr.bin/awk/awk.1, Revision 1.21
1.21 ! jmc 1: .\" $OpenBSD: awk.1,v 1.20 2003/12/19 12:48:02 jmc Exp $
1.7 aaron 2: .\" EX/EE is a Bd
1.11 jmc 3: .\"
4: .\" Copyright (C) Lucent Technologies 1997
5: .\" All Rights Reserved
1.12 jmc 6: .\"
1.11 jmc 7: .\" Permission to use, copy, modify, and distribute this software and
8: .\" its documentation for any purpose and without fee is hereby
9: .\" granted, provided that the above copyright notice appear in all
10: .\" copies and that both that the copyright notice and this
11: .\" permission notice and warranty disclaimer appear in supporting
12: .\" documentation, and that the name Lucent Technologies or any of
13: .\" its entities not be used in advertising or publicity pertaining
14: .\" to distribution of the software without specific, written prior
15: .\" permission.
1.12 jmc 16: .\"
1.11 jmc 17: .\" LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
18: .\" INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
19: .\" IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
20: .\" SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
21: .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
22: .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
23: .\" ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
24: .\" THIS SOFTWARE.
25: .\"
1.7 aaron 26: .Dd June 29, 1996
27: .Dt AWK 1
28: .Os
29: .Sh NAME
30: .Nm awk
31: .Nd pattern-directed scanning and processing language
32: .Sh SYNOPSIS
33: .Nm awk
1.16 jmc 34: .Op Fl safe
35: .Op Fl V
36: .Op Fl d Ns Op Ar n
1.7 aaron 37: .Op Fl F Ar fs
1.16 jmc 38: .Oo Fl v Ar var Ns =
39: .Ns Ar value Oc
1.18 jmc 40: .Op Ar prog | Fl f Ar progfile
1.7 aaron 41: .Ar
42: .Nm nawk
43: .Ar ...
44: .Sh DESCRIPTION
45: .Nm
1.1 tholo 46: scans each input
1.7 aaron 47: .Ar file
1.1 tholo 48: for lines that match any of a set of patterns specified literally in
1.7 aaron 49: .Ar prog
1.16 jmc 50: or in one or more files specified as
1.7 aaron 51: .Fl f Ar progfile .
1.16 jmc 52: With each pattern there can be an associated action that will be performed
1.1 tholo 53: when a line of a
1.7 aaron 54: .Ar file
1.1 tholo 55: matches the pattern.
56: Each line is matched against the
57: pattern portion of every pattern-action statement;
58: the associated action is performed for each matched pattern.
1.6 aaron 59: The file name
1.16 jmc 60: .Sq -
1.1 tholo 61: means the standard input.
62: Any
1.7 aaron 63: .Ar file
1.1 tholo 64: of the form
1.16 jmc 65: .Ar var Ns = Ns Ar value
1.1 tholo 66: is treated as an assignment, not a filename,
67: and is executed at the time it would have been opened if it were a filename.
1.16 jmc 68: .Pp
69: The options are as follows:
1.20 jmc 70: .Bl -tag -width "-safe "
1.16 jmc 71: .It Fl d Ns Op Ar n
72: Debug mode.
73: Set debug level to
74: .Ar n ,
75: or 1 if
76: .Ar n
77: is not specified.
78: A value greater than 1 causes
79: .Nm
80: to dump core on fatal errors.
81: .It Fl F Ar fs
82: Define the input field separator to be the regular expression
1.7 aaron 83: .Ar fs .
1.16 jmc 84: .It Fl f Ar filename
85: Read program code from the specified file
86: .Ar filename
87: instead of from the command line.
88: .It Fl safe
89: Disable file output
1.17 jmc 90: .Pf ( Ic print No > ,
91: .Ic print No >> ) ,
1.7 aaron 92: process creation
93: .Po
1.17 jmc 94: .Ar cmd | Ic getline ,
95: .Ic print No \&| ,
96: .Ic system
1.7 aaron 97: .Pc
98: and access to the environment
1.17 jmc 99: .Pf ( Va ENVIRON ;
1.18 jmc 100: see the section on variables below).
1.17 jmc 101: This is a first
1.16 jmc 102: .Pq and not very reliable
103: approximation to a
1.7 aaron 104: .Dq safe
105: version of
1.16 jmc 106: .Nm .
107: .It Fl V
108: Print the version number of
109: .Nm
110: to standard output and exit.
111: .It Fl v Ar var Ns = Ns Ar value
112: Assign
113: .Ar value
114: to variable
115: .Ar var
116: before
117: .Ar prog
118: is executed;
119: any number of
120: .Fl v
121: options may be present.
122: .El
1.7 aaron 123: .Pp
1.18 jmc 124: The input is normally made up of input lines
125: .Pq records
126: separated by newlines, or by the value of
127: .Va RS .
128: If
129: .Va RS
130: is null, then any number of blank lines are used as the record separator,
131: and newlines are used as field separators
132: (in addition to the value of
133: .Va FS ) .
134: This is convenient when working with multi-line records.
135: .Pp
1.7 aaron 136: An input line is normally made up of fields separated by whitespace,
1.18 jmc 137: or by the regular expression
1.7 aaron 138: .Va FS .
1.1 tholo 139: The fields are denoted
1.7 aaron 140: .Va $1 , $2 , ... ,
141: while
142: .Va $0
1.1 tholo 143: refers to the entire line.
144: If
1.7 aaron 145: .Va FS
1.1 tholo 146: is null, the input line is split into one field per character.
1.7 aaron 147: .Pp
1.18 jmc 148: Normally, any number of blanks separate fields.
149: In order to set the field separator to a single blank, use the
150: .Fl F
151: option with a value of
152: .Sq [\ \&] .
153: If a field separator of
154: .Sq t
155: is specified,
156: .Nm
157: treats it as if
158: .Sq \et
159: had been specified and uses
160: .Aq TAB
161: as the field separator.
162: In order to use a literal
163: .Sq t
164: as the field separator, use the
165: .Fl F
166: option with a value of
167: .Sq [t] .
168: .Pp
1.1 tholo 169: A pattern-action statement has the form
1.7 aaron 170: .Pp
171: .D1 Ar pattern Ic \&{ Ar action Ic \&}
172: .Pp
1.6 aaron 173: A missing
1.7 aaron 174: .Ic \&{ Ar action Ic \&}
1.1 tholo 175: means print the line;
176: a missing pattern always matches.
177: Pattern-action statements are separated by newlines or semicolons.
1.7 aaron 178: .Pp
1.18 jmc 179: Newlines are permitted after a terminating statement or following a comma
180: .Pq Sq ,\& ,
181: an open brace
182: .Pq Sq { ,
183: a logical AND
184: .Pq Sq && ,
185: a logical OR
186: .Pq Sq || ,
187: after the
188: .Sq do
189: or
190: .Sq else
191: keywords,
192: or after the closing parenthesis of an
193: .Sq if ,
194: .Sq for ,
195: or
196: .Sq while
197: statement.
198: Additionally, a backslash
199: .Pq Sq \e
200: can be used to escape a newline between tokens.
201: .Pp
1.1 tholo 202: An action is a sequence of statements.
203: A statement can be one of the following:
1.7 aaron 204: .Bd -unfilled -offset indent
205: .Ic if ( Xo
206: .Ar expression ) statement \&
207: .Op Ic else Ar statement
208: .Xc
209: .Ic while ( Ar expression ) statement
210: .Ic for ( Xo
211: .Ar expression ; expression ; expression ) statement
212: .Xc
213: .Ic for ( Xo
214: .Ar var Ic in Ar array ) statement
215: .Xc
216: .Ic do Ar statement Ic while ( Ar expression )
217: .Ic break
218: .Ic continue
219: .Ic { Oo Ar statement ... Oc Ic \& }
220: .Ar expression Xo
221: .No "# commonly" \&
222: .Ar var Ic = Ar expression
223: .Xc
224: .Ic print Xo
225: .Op Ar expression-list
1.17 jmc 226: .Op > Ns Ar expression
1.7 aaron 227: .Xc
228: .Ic printf Ar format Xo
229: .Op Ar ... , expression-list
1.17 jmc 230: .Op > Ns Ar expression
1.7 aaron 231: .Xc
232: .Ic return Op Ar expression
233: .Ic next Xo
234: .No "# skip remaining patterns on this input line"
235: .Xc
236: .Ic nextfile Xo
237: .No "# skip rest of this file, open next, start at top"
238: .Xc
239: .Ic delete Ar array Ns Xo
240: .Ic \&[ Ns Ar expression Ns Ic \&]
241: .No \& "# delete an array element"
242: .Xc
243: .Ic delete Ar array Xo
244: .No "# delete all elements of array"
245: .Xc
246: .Ic exit Xo
247: .Op Ar expression
248: .No \& "# exit immediately; status is" Ar expression
249: .Xc
250: .Ed
251: .Pp
1.1 tholo 252: Statements are terminated by
253: semicolons, newlines or right braces.
254: An empty
1.7 aaron 255: .Ar expression-list
1.1 tholo 256: stands for
1.7 aaron 257: .Ar $0 .
258: String constants are quoted
259: .Li \&"" ,
1.20 jmc 260: with the usual C escapes recognized within
261: (see
262: .Xr printf 1
263: for a complete list of these).
1.1 tholo 264: Expressions take on string or numeric values as appropriate,
265: and are built using the operators
1.7 aaron 266: .Ic + \- * / % ^
1.20 jmc 267: .Pq exponentiation ,
268: and concatenation
269: .Pq indicated by whitespace .
1.1 tholo 270: The operators
1.16 jmc 271: .Ic \&! ++ \-\- += \-= *= /= %= ^=
272: .Ic > >= < <= == != ?:
1.1 tholo 273: are also available in expressions.
274: Variables may be scalars, array elements
275: (denoted
1.7 aaron 276: .Li x[i] )
1.1 tholo 277: or fields.
278: Variables are initialized to the null string.
279: Array subscripts may be any string,
280: not necessarily numeric;
281: this allows for a form of associative memory.
282: Multiple subscripts such as
1.7 aaron 283: .Li [i,j,k]
1.1 tholo 284: are permitted; the constituents are concatenated,
285: separated by the value of
1.17 jmc 286: .Va SUBSEP
1.18 jmc 287: .Pq see the section on variables below ) .
1.7 aaron 288: .Pp
1.1 tholo 289: The
1.7 aaron 290: .Ic print
1.1 tholo 291: statement prints its arguments on the standard output
292: (or on a file if
1.17 jmc 293: .Pf > Ns Ar file
1.1 tholo 294: or
1.17 jmc 295: .Pf >> Ns Ar file
1.1 tholo 296: is present or on a pipe if
1.17 jmc 297: .Pf |\ \& Ar cmd
1.1 tholo 298: is present), separated by the current output field separator,
299: and terminated by the output record separator.
1.7 aaron 300: .Ar file
1.1 tholo 301: and
1.7 aaron 302: .Ar cmd
1.1 tholo 303: may be literal names or parenthesized expressions;
304: identical string values in different statements denote
305: the same open file.
306: The
1.7 aaron 307: .Ic printf
1.1 tholo 308: statement formats its expression list according to the format
309: (see
1.10 pvalchev 310: .Xr printf 3 ) .
1.18 jmc 311: .Pp
312: Patterns are arbitrary Boolean combinations
313: (with
314: .Ic "\&! || &&" )
315: of regular expressions and
316: relational expressions.
317: Regular expressions are as in
318: .Xr egrep 1 .
319: Isolated regular expressions
320: in a pattern apply to the entire line.
321: Regular expressions may also occur in
322: relational expressions, using the operators
323: .Ic ~
324: and
325: .Ic !~ .
326: .Pf / Ns Ar re Ns /
327: is a constant regular expression;
328: any string (constant or variable) may be used
329: as a regular expression, except in the position of an isolated regular expression
330: in a pattern.
331: .Pp
332: A pattern may consist of two patterns separated by a comma;
333: in this case, the action is performed for all lines
334: from an occurrence of the first pattern
335: through an occurrence of the second.
336: .Pp
337: A relational expression is one of the following:
338: .Bd -unfilled -offset indent
339: .Ar expression matchop regular-expression
340: .Ar expression relop expression
341: .Ar expression Ic in Ar array-name
342: .Ic \&( Ns Xo
343: .Ar expr , expr , \&... Ns Ic \&) in
344: .Ar \& array-name
345: .Xc
346: .Ed
347: .Pp
348: where a
349: .Ar relop
350: is any of the six relational operators in C, and a
351: .Ar matchop
352: is either
353: .Ic ~
354: (matches)
355: or
356: .Ic !~
357: (does not match).
358: A conditional is an arithmetic expression,
359: a relational expression,
360: or a Boolean combination
361: of these.
362: .Pp
363: The special patterns
364: .Ic BEGIN
365: and
366: .Ic END
367: may be used to capture control before the first input line is read
368: and after the last.
369: .Ic BEGIN
370: and
371: .Ic END
372: do not combine with other patterns.
373: .Pp
374: Variable names with special meanings:
375: .Pp
1.20 jmc 376: .Bl -tag -width "FILENAME " -compact
1.18 jmc 377: .It Va ARGC
378: Argument count, assignable.
379: .It Va ARGV
380: Argument array, assignable;
381: non-null members are taken as filenames.
382: .It Va CONVFMT
383: Conversion format when converting numbers
384: (default
385: .Qq Li %.6g ) .
386: .It Va ENVIRON
387: Array of environment variables; subscripts are names.
388: .It Va FILENAME
389: The name of the current input file.
390: .It Va FNR
391: Ordinal number of the current record in the current file.
392: .It Va FS
393: Regular expression used to separate fields; also settable
394: by option
395: .Fl F Ar fs .
396: .It Va NF
397: Number of fields in the current record.
398: .Va $NF
399: can be used to obtain the value of the last field in the current record.
400: .It Va NR
401: Ordinal number of the current record.
402: .It Va OFMT
403: Output format for numbers (default
404: .Qq Li %.6g ) .
405: .It Va OFS
406: Output field separator (default blank).
407: .It Va ORS
408: Output record separator (default newline).
409: .It Va RLENGTH
410: The length of the string matched by the
411: .Fn match
412: function.
413: .It Va RS
414: Input record separator (default newline).
415: .It Va RSTART
416: The starting position of the string matched by the
417: .Fn match
418: function.
419: .It Va SUBSEP
420: Separates multiple subscripts (default 034).
421: .El
1.17 jmc 422: .Sh FUNCTIONS
423: The awk language has a variety of built-in functions:
424: arithmetic, string, input/output and general.
425: .Ss Arithmetic Functions
426: .Bl -tag -width "atan2(y, x)"
427: .It Fn atan2 y x
428: Return the arctangent of
429: .Fa y Ns / Ns Fa x
430: in radians.
431: .It Fn cos x
432: Return the cosine of
433: .Fa x ,
434: where
435: .Fa x
436: is in radians.
437: .It Fn exp x
438: Return the exponential of
439: .Fa x .
440: .It Fn int x
441: Return
442: .Fa x
443: truncated to an integer value.
444: .It Fn log x
445: Return the natural logarithm of
446: .Fa x .
1.7 aaron 447: .It Fn rand
1.17 jmc 448: Return a random number,
449: .Fa n ,
450: such that
451: .Sm off
452: .Pf 0 \*(Le Fa n No \*(Lt 1 .
453: .Sm on
454: .It Fn sin x
455: Return the sine of
456: .Fa x ,
457: where
458: .Fa x
459: is in radians.
460: .It Fn sqrt x
461: Return the square root of
462: .Fa x .
463: .It Fn srand expr
1.16 jmc 464: Sets seed for
1.7 aaron 465: .Fn rand
1.17 jmc 466: to
467: .Fa expr
1.1 tholo 468: and returns the previous seed.
1.17 jmc 469: If
470: .Fa expr
471: is omitted, the time of day is used instead.
472: .El
473: .Ss String Functions
474: .Bl -tag -width "split(s, a, fs)"
475: .It Fn gsub r t s
476: The same as
477: .Fn sub
478: except that all occurrences of the regular expression are replaced.
479: .Fn gsub
480: returns the number of replacements.
1.7 aaron 481: .It Fn index s t
1.16 jmc 482: The position in
1.7 aaron 483: .Fa s
1.1 tholo 484: where the string
1.7 aaron 485: .Fa t
1.1 tholo 486: occurs, or 0 if it does not.
1.17 jmc 487: .It Fn length s
488: The length of
489: .Fa s
490: taken as a string,
491: or of
492: .Va $0
493: if no argument is given.
1.7 aaron 494: .It Fn match s r
1.16 jmc 495: The position in
1.7 aaron 496: .Fa s
1.1 tholo 497: where the regular expression
1.7 aaron 498: .Fa r
1.1 tholo 499: occurs, or 0 if it does not.
1.17 jmc 500: The variable
1.7 aaron 501: .Va RSTART
1.17 jmc 502: is set to the starting position of the matched string
503: .Pq which is the same as the returned value
504: or zero if no match is found.
505: The variable
1.7 aaron 506: .Va RLENGTH
1.17 jmc 507: is set to the length of the matched string,
508: or \-1 if no match is found.
1.7 aaron 509: .It Fn split s a fs
1.16 jmc 510: Splits the string
1.7 aaron 511: .Fa s
1.1 tholo 512: into array elements
1.7 aaron 513: .Va a[1] , a[2] , ... , a[n]
1.1 tholo 514: and returns
1.7 aaron 515: .Va n .
1.1 tholo 516: The separation is done with the regular expression
1.7 aaron 517: .Ar fs
1.1 tholo 518: or with the field separator
1.7 aaron 519: .Va FS
1.1 tholo 520: if
1.7 aaron 521: .Ar fs
1.1 tholo 522: is not given.
523: An empty string as field separator splits the string
524: into one array element per character.
1.17 jmc 525: .It Fn sprintf fmt expr ...
526: The string resulting from formatting
527: .Fa expr , ...
528: according to the
529: .Xr printf 3
530: format
531: .Fa fmt .
1.7 aaron 532: .It Fn sub r t s
1.16 jmc 533: Substitutes
1.7 aaron 534: .Fa t
1.1 tholo 535: for the first occurrence of the regular expression
1.7 aaron 536: .Fa r
1.1 tholo 537: in the string
1.7 aaron 538: .Fa s .
1.1 tholo 539: If
1.7 aaron 540: .Fa s
1.1 tholo 541: is not given,
1.7 aaron 542: .Va $0
1.1 tholo 543: is used.
1.17 jmc 544: An ampersand
545: .Pq Sq &
546: in
547: .Fa t
548: is replaced in string
549: .Fa s
550: with regular expression
551: .Fa r .
552: A literal ampersand can be specified by preceding it with two backslashes
553: .Pq Sq \e\e .
554: A literal backslash can be specified by preceding it with another backslash
555: .Pq Sq \e\e .
1.7 aaron 556: .Fn sub
1.17 jmc 557: returns the number of replacements.
558: .It Fn substr s m n
559: Return at most the
560: .Fa n Ns -character
561: substring of
562: .Fa s
563: that begins at position
564: .Fa m
565: counted from 1.
566: If
567: .Fa n
568: is omitted, or if
569: .Fa n
570: specifies more characters than are left in the string,
571: the length of the substring is limited by the length of
572: .Fa s .
1.7 aaron 573: .It Fn tolower str
1.16 jmc 574: Returns a copy of
1.7 aaron 575: .Fa str
1.1 tholo 576: with all upper-case characters translated to their
577: corresponding lower-case equivalents.
1.7 aaron 578: .It Fn toupper str
1.16 jmc 579: Returns a copy of
1.7 aaron 580: .Fa str
1.1 tholo 581: with all lower-case characters translated to their
582: corresponding upper-case equivalents.
1.7 aaron 583: .El
1.17 jmc 584: .Ss Input/Output and General Functions
585: .Bl -tag -width "getline [var] < file"
586: .It Fn close expr
587: Closes the file or pipe
588: .Fa expr .
589: .Fa expr
590: should match the string that was used to open the file or pipe.
591: .It Ar cmd | Ic getline Op Va var
592: Read a record of input from a stream piped from the output of
593: .Ar cmd .
594: If
595: .Va var
596: is omitted, the variables
597: .Va $0
598: and
599: .Va NF
600: are set.
601: Otherwise
602: .Va var
603: is set.
604: If the stream is not open, it is opened.
605: As long as the stream remains open, subsequent calls
606: will read subsequent records from the stream.
607: The stream remains open until explicitly closed with a call to
608: .Fn close .
609: .It Fn fflush expr
610: Flushes any buffered output for the file or pipe
611: .Fa expr .
612: .Fa expr
613: should match the string that was used to open the file or pipe.
614: .It Ic getline
615: Sets
616: .Va $0
617: to the next input record from the current input file.
618: This form of
619: .Ic getline
620: sets the variables
621: .Va NF ,
622: .Va NR ,
623: and
624: .Va FNR .
1.7 aaron 625: .Ic getline
1.17 jmc 626: returns 1 for a successful input, 0 for end of file, and \-1 for an error.
627: .It Ic getline Va var
628: Sets
1.7 aaron 629: .Va $0
1.17 jmc 630: to variable
631: .Va var .
632: This form of
633: .Ic getline
634: sets the variables
635: .Va NR
636: and
637: .Va FNR .
638: .Ic getline
639: returns 1 for a successful input, 0 for end of file, and \-1 for an error.
640: .It Xo
641: .Ic getline Op Va var
642: .Pf \ \&< Ar file
643: .Xc
644: Sets
1.7 aaron 645: .Va $0
1.1 tholo 646: to the next record from
1.7 aaron 647: .Ar file .
1.17 jmc 648: If
649: .Va var
650: is omitted, the variables
651: .Va $0
652: and
653: .Va NF
654: are set.
655: Otherwise
656: .Va var
657: is set.
658: If
659: .Ar file
660: is not open, it is opened.
661: As long as the stream remains open, subsequent calls will read subsequent
662: records from
663: .Ar file .
664: .Ar file
665: remains open until explicitly closed with a call to
666: .Fn close .
667: .It Fn system cmd
668: Executes
669: .Fa cmd
670: and returns its exit status.
671: .El
672: .Pp
673: Functions may be defined (at the position of a pattern-action statement)
674: thusly:
675: .Pp
676: .Dl function foo(a, b, c) { ...; return x }
1.7 aaron 677: .Pp
1.17 jmc 678: Parameters are passed by value if scalar, and by reference if array name;
679: functions may be called recursively.
680: Parameters are local to the function; all other variables are global.
681: Thus local variables may be created by providing excess parameters in
682: the function definition.
1.7 aaron 683: .Sh EXAMPLES
1.16 jmc 684: Print lines longer than 72 characters:
685: .Pp
1.7 aaron 686: .Dl length($0) > 72
1.16 jmc 687: .Pp
688: Print first two fields in opposite order:
1.7 aaron 689: .Pp
690: .Dl { print $2, $1 }
1.16 jmc 691: .Pp
692: Same, with input fields separated by comma and/or blanks and tabs:
1.7 aaron 693: .Bd -literal -offset indent
1.1 tholo 694: BEGIN { FS = ",[ \et]*|[ \et]+" }
695: { print $2, $1 }
1.7 aaron 696: .Ed
1.16 jmc 697: .Pp
698: Add up first column, print sum and average:
1.7 aaron 699: .Bd -literal -offset indent
700: { s += $1 }
701: END { print "sum is", s, " average is", s/NR }
702: .Ed
1.16 jmc 703: .Pp
704: Print all lines between start/stop pairs:
1.7 aaron 705: .Pp
706: .Dl /start/, /stop/
1.16 jmc 707: .Pp
708: Simulate echo(1):
1.7 aaron 709: .Bd -literal -offset indent
710: BEGIN { # Simulate echo(1)
711: for (i = 1; i < ARGC; i++) printf "%s ", ARGV[i]
712: printf "\en"
713: exit }
1.19 jmc 714: .Ed
715: .Pp
716: Print an error message to standard error:
717: .Bd -literal -offset indent
718: { print "error!" > "/dev/stderr" }
1.7 aaron 719: .Ed
720: .Sh SEE ALSO
1.16 jmc 721: .Xr egrep 1 ,
1.7 aaron 722: .Xr lex 1 ,
1.20 jmc 723: .Xr printf 1 ,
1.16 jmc 724: .Xr sed 1 ,
725: .Xr printf 3
1.21 ! jmc 726: .Pp
! 727: "Awk \(em A Pattern Scanning and Processing Language",
! 728: .Pa /usr/share/doc/usd/16.awk/ .
1.7 aaron 729: .Rs
730: .%A A. V. Aho
731: .%A B. W. Kernighan
732: .%A P. J. Weinberger
733: .%T The AWK Programming Language
734: .%I Addison-Wesley
735: .%D 1988
736: .%O ISBN 0-201-07981-X
737: .Re
1.8 aaron 738: .Sh HISTORY
1.13 millert 739: An
1.8 aaron 740: .Nm
1.13 millert 741: utility appeared in
742: .At v7 .
1.7 aaron 743: .Sh BUGS
1.1 tholo 744: There are no explicit conversions between numbers and strings.
745: To force an expression to be treated as a number add 0 to it;
746: to force it to be treated as a string concatenate
1.7 aaron 747: .Li \&""
748: to it.
749: .Pp
1.1 tholo 750: The scope rules for variables in functions are a botch;
751: the syntax is worse.
![[BACK]](/icons/back.gif){kind=icon}
Return to awk.1 CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / awk