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

and mark it as finished in the README.

README

@@ -33,7 +33,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
 =* false           yes                             none
 #* fold            yes                             none
 =* grep            yes                             none
-   head            yes                             none
+=* head            yes                             none
 =  hostname        non-posix                       none
 =* kill            yes                             none
 =  link            yes                             none

head.1

@@ -1,18 +1,43 @@
-.TH HEAD 1 sbase\-VERSION
-.SH NAME
-head \- output first part of files
-.SH SYNOPSIS
-.B head
-.RB [ \-n
-.IR lines ]
-.RI [ file ...]
-.SH DESCRIPTION
-.B head
-writes the first 10 lines of each file to stdout.  If no file is given, head
+.Dd January 25, 2015
+.Dt HEAD 1 sbase\-VERSION
+.Sh NAME
+.Nm head
+.Nd display initial lines of files
+.Sh SYNOPSIS
+.Nm head
+.Op Fl n Ar num
+.Op Fl N
+.Op Ar file ...
+.Sh DESCRIPTION
+.Nm
+writes
+.Ar num
+|
+.Sy N
+lines of each
+.Ar file
+to stdout.
+If no file is given
+.Nm
 reads from stdin.
-.SH OPTIONS
-.TP
-.BI \-n " lines"
-outputs the given number of lines.
-.SH SEE ALSO
-.IR tail (1)
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl n Ar num | Fl N
+Display
+.Ar num
+|
+.Sy N
+lines. Default is 10.
+.El
+.Sh SEE ALSO
+.Xr tail 1
+.Sh STANDARDS
+The
+.Nm
+utility is compliant with the
+.St -p1003.1-2008
+specification.
+.Pp
+The
+.Op Fl N
+flag is an extension to that specification.

head.c

@@ -4,15 +4,30 @@
 #include <string.h>
 #include <unistd.h>
 
-#include "text.h"
 #include "util.h"
 
-static void head(FILE *, const char *, long);
+static void
+head(FILE *fp, const char *str, long n)
+{
+	char *buf = NULL;
+	size_t size = 0;
+	ssize_t len;
+	unsigned long i = 0;
+
+	while (i < n && ((len = getline(&buf, &size, fp)) != -1)) {
+		fputs(buf, stdout);
+		if (buf[len - 1] == '\n')
+			i++;
+	}
+	free(buf);
+	if (ferror(fp))
+		eprintf("%s: read error:", str);
+}
 
 static void
 usage(void)
 {
-	eprintf("usage: %s [-n lines] [file...]\n", argv0);
+	eprintf("usage: %s [-n lines] [-N] [file...]\n", argv0);
 }
 
 int
@@ -54,21 +69,3 @@ main(int argc, char *argv[])
 	}
 	return ret;
 }
-
-static void
-head(FILE *fp, const char *str, long n)
-{
-	char *buf = NULL;
-	size_t size = 0;
-	ssize_t len;
-	unsigned long i = 0;
-
-	while (i < n && ((len = getline(&buf, &size, fp)) != -1)) {
-		fputs(buf, stdout);
-		if (buf[len - 1] == '\n')
-			i++;
-	}
-	free(buf);
-	if (ferror(fp))
-		eprintf("%s: read error:", str);
-}