Today someone bumped into a port that contained head -c calls. While
upstream could be prodded to care a bit more about portability, support
for head -c is widespread (GNU coreutils, busybox, FreeBSD, NetBSD) so
I don't see any value in being different. Plus, tail(1) already has
support for -c.
Comments/ok?
PS: the next diff will remove documentation for the obsolete "-count"
syntax.
Index: head.1
===================================================================
RCS file: /cvs/src/usr.bin/head/head.1,v
retrieving revision 1.23
diff -u -p -r1.23 head.1
--- head.1 25 Oct 2015 21:50:32 -0000 1.23
+++ head.1 9 Mar 2016 20:02:08 -0000
@@ -37,7 +37,7 @@
.Nd display first few lines of files
.Sh SYNOPSIS
.Nm head
-.Op Fl Ar count | Fl n Ar count
+.Op Fl c Ar count | Fl Ar count | Fl n Ar count
.Op Ar
.Sh DESCRIPTION
The
@@ -56,6 +56,12 @@ is omitted, it defaults to 10.
.Pp
The options are as follows:
.Bl -tag -width Ds
+.It Fl c Ar count
+Copy the first
+.Ar count
+bytes of each input file to the standard output.
+.Ar count
+must be a positive decimal integer.
.It Fl Ar count | Fl n Ar count
Copy the first
.Ar count
Index: head.c
===================================================================
RCS file: /cvs/src/usr.bin/head/head.c,v
retrieving revision 1.20
diff -u -p -r1.20 head.c
--- head.c 9 Oct 2015 01:37:07 -0000 1.20
+++ head.c 9 Mar 2016 20:02:08 -0000
@@ -40,7 +40,7 @@
static void usage(void);
/*
- * head - give the first few lines of a stream or of each of a set of files
+ * head - give the first few bytes/lines of a stream or of each of a set of
files
*
* Bill Joy UCB August 24, 1977
*/
@@ -51,9 +51,9 @@ main(int argc, char *argv[])
FILE *fp;
long cnt;
int ch, firsttime;
- long linecnt = 10;
+ long count = 10;
char *p = NULL;
- int status = 0;
+ int dobytes = 0, status = 0;
if (pledge("stdio rpath", NULL) == -1)
err(1, "pledge");
@@ -66,13 +66,18 @@ main(int argc, char *argv[])
argv++;
}
- while ((ch = getopt(argc, argv, "n:")) != -1) {
+ while ((ch = getopt(argc, argv, "c:n:")) != -1) {
switch (ch) {
+ case 'c':
+ dobytes = 1;
+ p = optarg;
+ break;
case 'n':
+ dobytes = 0;
p = optarg;
break;
default:
- usage();
+ usage();
}
}
argc -= optind, argv += optind;
@@ -80,9 +85,10 @@ main(int argc, char *argv[])
if (p) {
const char *errstr;
- linecnt = strtonum(p, 1, LONG_MAX, &errstr);
+ count = strtonum(p, 1, LONG_MAX, &errstr);
if (errstr)
- errx(1, "line count %s: %s", errstr, p);
+ errx(1, "%s count %s: %s", dobytes ? "bytes" : "lines",
+ errstr, p);
}
for (firsttime = 1; ; firsttime = 0) {
@@ -105,10 +111,16 @@ main(int argc, char *argv[])
}
++argv;
}
- for (cnt = linecnt; cnt && !feof(fp); --cnt)
- while ((ch = getc(fp)) != EOF)
- if (putchar(ch) == '\n')
- break;
+ if (dobytes) {
+ for (cnt = count; cnt && !feof(fp); --cnt)
+ if ((ch = getc(fp)) != EOF)
+ putchar(ch);
+ } else {
+ for (cnt = count; cnt && !feof(fp); --cnt)
+ while ((ch = getc(fp)) != EOF)
+ if (putchar(ch) == '\n')
+ break;
+ }
fclose(fp);
}
/*NOTREACHED*/
@@ -118,6 +130,7 @@ main(int argc, char *argv[])
static void
usage(void)
{
- fputs("usage: head [-count | -n count] [file ...]\n", stderr);
+ fputs("usage: head [-c count | -count | -n count] [file ...]\n",
+ stderr);
exit(1);
}
--
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
