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diff --git a/man-pages-posix-2017/man1p/uniq.1p b/man-pages-posix-2017/man1p/uniq.1p new file mode 100644 index 0000000..964ca0d --- /dev/null +++ b/man-pages-posix-2017/man1p/uniq.1p @@ -0,0 +1,408 @@ +'\" et +.TH UNIQ "1P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.\" +.SH NAME +uniq +\(em report or filter out repeated lines in a file +.SH SYNOPSIS +.LP +.nf +uniq \fB[\fR-c|-d|-u\fB] [\fR-f \fIfields\fB] [\fR-s \fIchar\fB] [\fIinput_file \fB[\fIoutput_file\fB]]\fR +.fi +.SH DESCRIPTION +The +.IR uniq +utility shall read an input file comparing adjacent lines, and write +one copy of each input line on the output. The second and succeeding +copies of repeated adjacent input lines shall not be written. +The trailing +<newline> +of each line in the input shall be ignored when doing comparisons. +.P +Repeated lines in the input shall not be detected if they are not +adjacent. +.SH OPTIONS +The +.IR uniq +utility shall conform to the Base Definitions volume of POSIX.1\(hy2017, +.IR "Section 12.2" ", " "Utility Syntax Guidelines", +except that +.BR '\(pl' +may be recognized as an option delimiter as well as +.BR '\-' . +.P +The following options shall be supported: +.IP "\fB\-c\fP" 10 +Precede each output line with a count of the number of times the line +occurred in the input. +.IP "\fB\-d\fP" 10 +Suppress the writing of lines that are not repeated in the input. +.IP "\fB\-f\ \fIfields\fR" 10 +Ignore the first +.IR fields +fields on each input line when doing comparisons, where +.IR fields +is a positive decimal integer. A field is the maximal string matched +by the basic regular expression: +.RS 10 +.sp +.RS 4 +.nf + +[[:blank:]]*[\(ha[:blank:]]* +.fi +.P +.RE +.P +If the +.IR fields +option-argument specifies more fields than appear on an input line, a +null string shall be used for comparison. +.RE +.IP "\fB\-s\ \fIchars\fR" 10 +Ignore the first +.IR chars +characters when doing comparisons, where +.IR chars +shall be a positive decimal integer. If specified in conjunction with +the +.BR \-f +option, the first +.IR chars +characters after the first +.IR fields +fields shall be ignored. If the +.IR chars +option-argument specifies more characters than remain on an input line, +a null string shall be used for comparison. +.IP "\fB\-u\fP" 10 +Suppress the writing of lines that are repeated in the input. +.SH OPERANDS +The following operands shall be supported: +.IP "\fIinput_file\fR" 10 +A pathname of the input file. If the +.IR input_file +operand is not specified, or if the +.IR input_file +is +.BR '\-' , +the standard input shall be used. +.IP "\fIoutput_file\fR" 10 +A pathname of the output file. If the +.IR output_file +operand is not specified, the standard output shall be used. The +results are unspecified if the file named by +.IR output_file +is the file named by +.IR input_file . +.SH STDIN +The standard input shall be used only if no +.IR input_file +operand is specified or if +.IR input_file +is +.BR '\-' . +See the INPUT FILES section. +.SH "INPUT FILES" +The input file shall be a text file. +.SH "ENVIRONMENT VARIABLES" +The following environment variables shall affect the execution of +.IR uniq : +.IP "\fILANG\fP" 10 +Provide a default value for the internationalization variables that are +unset or null. (See the Base Definitions volume of POSIX.1\(hy2017, +.IR "Section 8.2" ", " "Internationalization Variables" +for the precedence of internationalization variables used to determine +the values of locale categories.) +.IP "\fILC_ALL\fP" 10 +If set to a non-empty string value, override the values of all the +other internationalization variables. +.IP "\fILC_CTYPE\fP" 10 +Determine the locale for the interpretation of sequences of bytes of +text data as characters (for example, single-byte as opposed to +multi-byte characters in arguments and input files) and which +characters constitute a +<blank> +in the current locale. +.IP "\fILC_MESSAGES\fP" 10 +.br +Determine the locale that should be used to affect the format and +contents of diagnostic messages written to standard error. +.IP "\fINLSPATH\fP" 10 +Determine the location of message catalogs for the processing of +.IR LC_MESSAGES . +.SH "ASYNCHRONOUS EVENTS" +Default. +.SH STDOUT +The standard output shall be used if no +.IR output_file +operand is specified, and shall be used if the +.IR output_file +operand is +.BR '\-' +and the implementation treats the +.BR '\-' +as meaning standard output. Otherwise, the standard output shall +not be used. +See the OUTPUT FILES section. +.SH STDERR +The standard error shall be used only for diagnostic messages. +.SH "OUTPUT FILES" +If the +.BR \-c +option is specified, the output file shall be empty or each line +shall be of the form: +.sp +.RS 4 +.nf + +"%d %s", <\fInumber of duplicates\fR>, <\fIline\fR> +.fi +.P +.RE +.P +otherwise, the output file shall be empty or each line shall be +of the form: +.sp +.RS 4 +.nf + +"%s", <\fIline\fR> +.fi +.P +.RE +.SH "EXTENDED DESCRIPTION" +None. +.SH "EXIT STATUS" +The following exit values shall be returned: +.IP "\00" 6 +The utility executed successfully. +.IP >0 6 +An error occurred. +.SH "CONSEQUENCES OF ERRORS" +Default. +.LP +.IR "The following sections are informative." +.SH "APPLICATION USAGE" +If the collating sequence of the current locale has a total ordering +of all characters, the +.IR sort +utility can be used to cause repeated lines to be adjacent in the input +file. If the collating sequence does not have a total ordering of all +characters, the +.IR sort +utility should still do this but it might not. To ensure that all +duplicate lines are eliminated, and have the output sorted according +the collating sequence of the current locale, applications should use: +.sp +.RS 4 +.nf + +LC_ALL=C sort -u | sort +.fi +.P +.RE +.P +instead of: +.sp +.RS 4 +.nf + +sort | uniq +.fi +.P +.RE +.P +To remove duplicate lines based on whether they collate equally +instead of whether they are identical, applications should use: +.sp +.RS 4 +.nf + +sort -u +.fi +.P +.RE +.P +instead of: +.sp +.RS 4 +.nf + +sort | uniq +.fi +.P +.RE +.P +When using +.IR uniq +to process pathnames, it is recommended that LC_ALL, or at least +LC_CTYPE and LC_COLLATE, are set to POSIX or C in the environment, +since pathnames can contain byte sequences that do not form valid +characters in some locales, in which case the utility's behavior would +be undefined. In the POSIX locale each byte is a valid single-byte +character, and therefore this problem is avoided. +.SH EXAMPLES +The following input file data (but flushed left) was used for a test +series on +.IR uniq : +.sp +.RS 4 +.nf + +#01 foo0 bar0 foo1 bar1 +#02 bar0 foo1 bar1 foo1 +#03 foo0 bar0 foo1 bar1 +#04 +#05 foo0 bar0 foo1 bar1 +#06 foo0 bar0 foo1 bar1 +#07 bar0 foo1 bar1 foo0 +.fi +.P +.RE +.P +What follows is a series of test invocations of the +.IR uniq +utility that use a mixture of +.IR uniq +options against the input file data. These tests verify the meaning of +.IR adjacent . +The +.IR uniq +utility views the input data as a sequence of strings delimited by +.BR '\en' . +Accordingly, for the +.IR fields th +member of the sequence, +.IR uniq +interprets unique or repeated adjacent lines strictly relative to the +.IR fields +1th +member. +.IP " 1." 4 +This first example tests the line counting option, comparing each line +of the input file data starting from the second field: +.RS 4 +.sp +.RS 4 +.nf + +uniq -c -f 1 uniq_0I.t + 1 #01 foo0 bar0 foo1 bar1 + 1 #02 bar0 foo1 bar1 foo1 + 1 #03 foo0 bar0 foo1 bar1 + 1 #04 + 2 #05 foo0 bar0 foo1 bar1 + 1 #07 bar0 foo1 bar1 foo0 +.fi +.P +.RE +.P +The number +.BR '2' , +prefixing the fifth line of output, signifies that the +.IR uniq +utility detected a pair of repeated lines. Given the input data, this +can only be true when +.IR uniq +is run using the +.BR "\-f\ 1" +option (which shall cause +.IR uniq +to ignore the first field on each input line). +.RE +.IP " 2." 4 +The second example tests the option to suppress unique lines, comparing +each line of the input file data starting from the second field: +.RS 4 +.sp +.RS 4 +.nf + +uniq -d -f 1 uniq_0I.t +#05 foo0 bar0 foo1 bar1 +.fi +.P +.RE +.RE +.IP " 3." 4 +This test suppresses repeated lines, comparing each line of the input +file data starting from the second field: +.RS 4 +.sp +.RS 4 +.nf + +uniq -u -f 1 uniq_0I.t +#01 foo0 bar0 foo1 bar1 +#02 bar0 foo1 bar1 foo1 +#03 foo0 bar0 foo1 bar1 +#04 +#07 bar0 foo1 bar1 foo0 +.fi +.P +.RE +.RE +.IP " 4." 4 +This suppresses unique lines, comparing each line of the input file +data starting from the third character: +.RS 4 +.sp +.RS 4 +.nf + +uniq -d -s 2 uniq_0I.t +.fi +.P +.RE +.P +In the last example, the +.IR uniq +utility found no input matching the above criteria. +.RE +.SH RATIONALE +Some historical implementations have limited lines to be 1\|080 bytes +in length, which does not meet the implied +{LINE_MAX} +limit. +.P +Earlier versions of this standard allowed the +.BR \- \c +.IR number +and +.BR \(pl \c +.IR number +options. These options are no longer specified by POSIX.1\(hy2008 but +may be present in some implementations. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "\fIcomm\fR\^", +.IR "\fIsort\fR\^" +.P +The Base Definitions volume of POSIX.1\(hy2017, +.IR "Chapter 8" ", " "Environment Variables", +.IR "Section 12.2" ", " "Utility Syntax Guidelines" +.\" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1-2017, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, 2018 Edition, +Copyright (C) 2018 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +In the event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . +.PP +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |