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[src/trunk]: src/bin/cat Add an option to read with a different buffer size, ...
details: https://anonhg.NetBSD.org/src/rev/10754d5a74c6
branches: trunk
changeset: 782637:10754d5a74c6
user: christos <christos%NetBSD.org@localhost>
date: Sat Nov 10 16:18:41 2012 +0000
description:
Add an option to read with a different buffer size, and document the
buffer size we use. This allows us to cat -B 10000000 /proc/<pid>/maps
for example which cannot handle seeking.
diffstat:
bin/cat/cat.1 | 10 ++++++++--
bin/cat/cat.c | 37 +++++++++++++++++++++----------------
2 files changed, 29 insertions(+), 18 deletions(-)
diffs (136 lines):
diff -r 471224eae766 -r 10754d5a74c6 bin/cat/cat.1
--- a/bin/cat/cat.1 Sat Nov 10 15:59:58 2012 +0000
+++ b/bin/cat/cat.1 Sat Nov 10 16:18:41 2012 +0000
@@ -1,4 +1,4 @@
-.\" $NetBSD: cat.1,v 1.34 2012/08/09 07:26:28 dholland Exp $
+.\" $NetBSD: cat.1,v 1.35 2012/11/10 16:18:41 christos Exp $
.\"
.\" Copyright (c) 1989, 1990, 1993
.\" The Regents of the University of California. All rights reserved.
@@ -32,7 +32,7 @@
.\"
.\" @(#)cat.1 8.3 (Berkeley) 5/2/95
.\"
-.Dd April 6, 2012
+.Dd November 10, 2012
.Dt CAT 1
.Os
.Sh NAME
@@ -40,6 +40,7 @@
.Nd concatenate and print files
.Sh SYNOPSIS
.Nm
+.Op Fl B Ar bsize
.Op Fl beflnstuv
.Op Fl
.Op Ar
@@ -65,6 +66,11 @@
.Pp
The options are as follows:
.Bl -tag -width Ds
+.It Fl B Ar bsize
+Read with a buffer size of
+.Ar bsize
+bytes, instead of the default buffer size which is the blocksize of the
+output file.
.It Fl b
Implies the
.Fl n
diff -r 471224eae766 -r 10754d5a74c6 bin/cat/cat.c
--- a/bin/cat/cat.c Sat Nov 10 15:59:58 2012 +0000
+++ b/bin/cat/cat.c Sat Nov 10 16:18:41 2012 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: cat.c,v 1.48 2012/03/17 23:35:28 christos Exp $ */
+/* $NetBSD: cat.c,v 1.49 2012/11/10 16:18:41 christos Exp $ */
/*
* Copyright (c) 1989, 1993
@@ -44,7 +44,7 @@
#if 0
static char sccsid[] = "@(#)cat.c 8.2 (Berkeley) 4/27/95";
#else
-__RCSID("$NetBSD: cat.c,v 1.48 2012/03/17 23:35:28 christos Exp $");
+__RCSID("$NetBSD: cat.c,v 1.49 2012/11/10 16:18:41 christos Exp $");
#endif
#endif /* not lint */
@@ -61,11 +61,11 @@
#include <string.h>
#include <unistd.h>
-int bflag, eflag, fflag, lflag, nflag, sflag, tflag, vflag;
-int rval;
-const char *filename;
+static int bflag, eflag, fflag, lflag, nflag, sflag, tflag, vflag;
+static size_t bsize;
+static int rval;
+static const char *filename;
-int main(int, char *[]);
void cook_args(char *argv[]);
void cook_buf(FILE *);
void raw_args(char *argv[]);
@@ -80,8 +80,11 @@
setprogname(argv[0]);
(void)setlocale(LC_ALL, "");
- while ((ch = getopt(argc, argv, "beflnstuv")) != -1)
+ while ((ch = getopt(argc, argv, "B:beflnstuv")) != -1)
switch (ch) {
+ case 'B':
+ bsize = (size_t)strtol(optarg, NULL, 0);
+ break;
case 'b':
bflag = nflag = 1; /* -b implies -n */
break;
@@ -112,9 +115,9 @@
default:
case '?':
(void)fprintf(stderr,
- "usage: cat [-beflnstuv] [-] [file ...]\n");
- exit(EXIT_FAILURE);
- /* NOTREACHED */
+ "Usage: %s [-B <bsize>] [-beflnstuv] [-] "
+ "[file ...]\n", getprogname());
+ return EXIT_FAILURE;
}
argv += optind;
@@ -133,7 +136,7 @@
raw_args(argv);
if (fclose(stdout))
err(EXIT_FAILURE, "stdout");
- return (rval);
+ return rval;
}
void
@@ -286,7 +289,6 @@
{
static char *buf;
static char fb_buf[BUFSIZ];
- static size_t bsize;
ssize_t nr, nw, off;
int wfd;
@@ -295,13 +297,16 @@
if (buf == NULL) {
struct stat sbuf;
- if (fstat(wfd, &sbuf) == 0 && sbuf.st_blksize > 0 &&
- (size_t)sbuf.st_blksize > sizeof(fb_buf)) {
- bsize = sbuf.st_blksize;
+ if (bsize == 0) {
+ if (fstat(wfd, &sbuf) == 0 && sbuf.st_blksize > 0 &&
+ (size_t)sbuf.st_blksize > sizeof(fb_buf))
+ bsize = sbuf.st_blksize;
+ }
+ if (bsize != 0)
buf = malloc(bsize);
- }
if (buf == NULL) {
bsize = sizeof(fb_buf);
+ warnx("malloc, using %zu buffer", bsize);
buf = fb_buf;
}
}
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