Add mandoc-manpage for cut(1) and clean up code

and mark it as finished in README.

README

@@ -21,7 +21,7 @@ The following tools are implemented (* == finished):
 * comm            yes                             none
   cp              no                              -H, -i, -L
 * cron            non-posix                       none
-  cut             yes                             none
+* cut             yes                             none
   date            yes                             none
   dirname         yes                             none
   du              no                              -H, -L, -x

cut.1

@@ -1,60 +1,70 @@
-.TH CUT 1 sbase\-VERSION
+.Dd January 18, 2015
-.SH NAME
+.Dt CUT 1 sbase\-VERSION
-cut \- extract columns of data
+.Sh NAME
-.SH SYNOPSIS
+.Nm cut
-.B cut \-b
+.Nd extract columns of data
-.I list
+.Sh SYNOPSIS
-.RB [ \-n ]
+.Nm cut
-.RI [ file ...]
+.Fl b Ar list
-.br
+.Op Fl n
-.B cut \-c
+.Op Ar file ...
-.I list
+.Nm cut
-.RI [ file ...]
+.Fl c Ar list
-.br
+.Op Ar file ...
-.B cut \-f
+.Nm cut
-.I list
+.Fl f Ar list
-.RB [ \-d
+.Op Fl d Ar delim
-.IR delim ]
+.Op Fl s
-.RB [ \-s ]
+.Op Ar file ...
-.RI [ file ...]
+.Sh DESCRIPTION
-.SH DESCRIPTION
+.Nm
-.B cut
+out bytes, characters or delimited fields from each line of
-out bytes, characters, or delimited fields from each line of the given
+.Ar file
-files and write to stdout. With no file, or when file is `-', cut reads
+and write to stdout.
-from stdin.
+.Pp
-.P
+If no
-.I list
+.Ar file
-is a comma or space separated list of numbers and ranges where numbering
+is given or
-starts from 1. Ranges are on the form `N-M'. If N or M is missing, the
+.Ar file
-beginning or end of line is assumed. Numbers and ranges may be repeated,
+is '-',
-overlapping, and in any order. Selected input is written in the same
+.Nm
-order that it is read, and is written exactly once.
+reads from stdin.
-.SH OPTIONS
+.Pp
-.TP
+.Ar list
-.BI \-b \ list
+is a comma or space separated list of numbers and ranges starting
-The
+from 1. Ranges have the form 'N-M'. If N or M is missing,
-.I list
+beginning or end of line is assumed. Numbers and ranges
-specifies byte positions.
+may be repeated, overlapping and in any order.
-.TP
+.Pp
-.BI \-c \ list
+Selected input is written in the same order it is read
-The
+and is written exactly once.
-.I list
+.Sh OPTIONS
-specifies character positions.
+.Bl -tag -width Ds
-.TP
+.It Fl b Ar list | Fl c Ar list
-.BI \-d \ delim
+.Ar list
+specifies byte | character positions.
+.It Fl n
+Do not split multibyte characters. A character is written when its
+last byte is selected.
+.It Fl f Ar list
+.Ar list
+specifies field numbers. Lines not containing field
+delimiters are passed through, unless
+.Fl s
+is specified.
+.It Fl d Ar delim
 Use first byte of
-.I delim
+.Ar delim
-as field delimiter, instead of tab.
+as field delimiter. Default is \et.
-.TP
+.It Fl s
-.BI \-f \ list
-The
-.I list
-specifies field numbers. Lines not containing field delimiters are
-passed through untouched.
-.TP
-.B \-n
-Do not split characters. A character is output if its last byte is
-selected.
-.TP
-.B \-s
 Suppress lines not containing field delimiters.
+.El
+.Sh STANDARDS
+The
+.Nm
+utility is compliant with the
+.St -p1003.1-2008
+specification.
+.Pp
+The possibility of separating numbers and ranges with a space
+is an extension to that specification.

cut.c

@@ -6,14 +6,6 @@
 #include "text.h"
 #include "util.h"
 
-static void
-usage(void)
-{
-	eprintf("usage: cut -b list [-n] [file...]\n"
-	        "       cut -c list [file...]\n"
-	        "       cut -f list [-d delim] [-s] [file...]\n");
-}
-
 typedef struct Range {
 	size_t min, max;
 	struct Range *next;
@@ -135,6 +127,14 @@ cut(FILE *fp)
 	}
 }
 
+static void
+usage(void)
+{
+	eprintf("usage: cut -b list [-n] [file ...]\n"
+	        "       cut -c list [file ...]\n"
+	        "       cut -f list [-d delim] [-s] [file ...]\n");
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -163,12 +163,12 @@ main(int argc, char *argv[])
 	if (!mode)
 		usage();
 
-	if (!argc) {
+	if (!argc)
 		cut(stdin);
-	} else for (; argc--; argv++) {
+	else for (; argc--; argv++) {
-		if (!strcmp(*argv, "-")) {
+		if (!strcmp(*argv, "-"))
 			cut(stdin);
-		} else {
+		else {
 			if (!(fp = fopen(*argv, "r"))) {
 				weprintf("fopen %s:", *argv);
 				continue;