diff options
Diffstat (limited to 'gawk.1')
| -rw-r--r-- | gawk.1 | 102 |
1 files changed, 86 insertions, 16 deletions
@@ -1,7 +1,7 @@ .ds PX \s-1POSIX\s+1 .ds UX \s-1UNIX\s+1 .ds AN \s-1ANSI\s+1 -.TH GAWK 1 "Jun 5 1991" "Free Software Foundation" "Utility Commands" +.TH GAWK 1 "Jul 20 1992" "Free Software Foundation" "Utility Commands" .SH NAME gawk \- pattern scanning and processing language .SH SYNOPSIS @@ -123,6 +123,9 @@ mode. In compatibility mode, behaves identically to \*(UX .IR awk ; none of the GNU-specific extensions are recognized. +See +.BR "GNU EXTENSIONS" , +below, for more information. .TP .PD 0 .B copyleft @@ -319,7 +322,7 @@ Assigning a new value to .B FS overrides the use of .BR FIELDWIDTHS , -and restores the default behaviour. +and restores the default behavior. .PP Each field in the input line may be referenced by its position, .BR $1 , @@ -721,7 +724,7 @@ inclusive. It does not combine with any other sort of pattern expression. Regular expressions are the extended kind found in .IR egrep . They are composed of characters as follows: -.TP \w'[^abc...]'u+1n +.TP \w'\fB[^\fIabc...\fB]\fR'u+2n .I c matches the non-metacharacter .IR c . @@ -932,6 +935,17 @@ AWK program. If the end of the input data is reached, the .B END block(s), if any, are executed. .TP +.B "next file" +Stop processing the current input file. The next input record read +comes from the next input file. +.B FILENAME +is updated, +.B FNR +is reset to 1, and processing starts over with the first pattern in the +AWK program. If the end of the input data is reached, the +.B END +block(s), if any, are executed. +.TP .B print Prints the current record. .TP @@ -971,7 +985,7 @@ pipes into .BR getline . .BR Getline will return 0 on end of file, and \-1 on an error. -.SS The \fIprintf\fP Statement +.SS The \fIprintf\fP\^ Statement .PP The AWK versions of the .B printf @@ -1082,7 +1096,7 @@ recognizes certain special filenames internally. These filenames allow access to open file descriptors inherited from .IR gawk 's parent process (usually the shell). The filenames are: -.TP \w'\fB/dev/fd/\^\fIn\fR'u+1n +.TP \w'\fB/dev/stdout\fR'u+1n .B /dev/stdin The standard input. .TP @@ -1093,7 +1107,7 @@ The standard output. The standard error output. .TP .BI /dev/fd/\^ n -The file denoted by the open file descriptor +The file associated with the open file descriptor .IR n . .PP These are particularly useful for error messages. For example: @@ -1255,7 +1269,7 @@ translated to their corresponding upper-case counterparts. Non-alphabetic characters are left unchanged. .SS Time Functions .PP -Since one of the primary uses of AWK programs in processing log files +Since one of the primary uses of AWK programs is processing log files that contain time stamp information, .I gawk provides the following two functions for obtaining time stamps and @@ -1421,7 +1435,7 @@ Alfred V. Aho, Brian W. Kernighan, Peter J. Weinberger, Addison-Wesley, 1988. ISBN 0-201-07981-X. .PP .IR "The GAWK Manual" , -published by the Free Software Foundation, 1991. +Edition 0.14, published by the Free Software Foundation, 1992. .SH POSIX COMPATIBILITY A primary goal for .I gawk @@ -1452,7 +1466,7 @@ block was run. Applications came to depend on this ``feature.'' When .I awk was changed to match its documentation, this option was added to -accomodate applications that depended upon the old behaviour. +accomodate applications that depended upon the old behavior. (This feature was agreed upon by both the AT&T and GNU developers.) .PP The @@ -1546,6 +1560,11 @@ No path search is performed for files named via the option. Therefore the .B AWKPATH environment variable is not special. +.TP +\(bu +The use of +.B "next file" +to abandon processing of the current input file. .RE .PP The AWK book does not define the return value of the @@ -1572,6 +1591,9 @@ option is ``t'', then .B FS will be set to the tab character. Since this is a rather ugly special case, it is not the default behavior. +This behavior also does not occur if +.B \-Wposix +has been specified. .ig .PP If @@ -1590,6 +1612,52 @@ This option should only be of interest to the maintainers, and may not even be compiled into .IR gawk . .. +.SH HISTORICAL FEATURES +There are two features of historical AWK implementations that +.I gawk +supports. +First, it is possible to call the +.B length() +built-in function not only with no argument, but even without parentheses! +Thus, +.RS +.PP +.ft B +a = length +.ft R +.RE +.PP +is the same as either of +.RS +.PP +.ft B +a = length() +.br +a = length($0) +.ft R +.RE +.PP +This feature is marked as ``deprecated'' in the \*(PX standard, and +.I gawk +will issue a warning about its use if +.B \-Wlint +is specified on the command line. +.PP +The other feature is the use of the +.B continue +statement outside the body of a +.BR while , +.BR for , +or +.B do +loop. Traditional AWK implementations have treated such usage as +equivalent to the +.B next +statement. +.I Gawk +will support this usage if +.B \-Wposix +has not been specified. .SH BUGS The .B \-F @@ -1598,9 +1666,9 @@ it remains only for backwards compatibility. .SH VERSION INFORMATION This man page documents .IR gawk , -version 2.13. +version 2.14. .PP -For the 2.13 version of +For the 2.14 version of .IR gawk , the .BR \-c , @@ -1615,9 +1683,7 @@ and options of the 2.11 version are recognized. However, .I gawk will print a warning message, -and these options will go away in the 2.14 version. -.PP -The 2.12 version was a development version that was not officially released. +and these options will go away in the 2.15 version. .SH AUTHORS The original version of \*(UX .I awk @@ -1632,11 +1698,15 @@ to be compatible with the original version of .I awk distributed in Seventh Edition \*(UX. John Woods contributed a number of bug fixes. -David Trueman of Dalhousie University, with contributions -from Arnold Robbins at Emory University and AudioFAX, made +David Trueman, with contributions +from Arnold Robbins, made .I gawk compatible with the new version of \*(UX .IR awk . +.PP +The initial DOS port was done by Conrad Kwok and Scott Garfinkle. +Scott Deifik is the current DOS maintainer. Pat Rankin did the +port to VMS, and Michal Jaegermann did the port to the Atari ST. .SH ACKNOWLEDGEMENTS Brian Kernighan of Bell Labs provided valuable assistance during testing and debugging. |