bekucera/coreutils
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/coreutils.git synced 2025-09-10 07:59:52 +02:00
Code Issues Packages Projects Releases Wiki Activity

maint: prefer 'read' to 'safe_read'

Browse Source 
In the old days, safe_read acted more like what full_read does now.
When that went away, some code that invoked safe_read should
have gone back to plain 'read' but I guess we never got around to it.
Simplify this code by going back to plain 'read'.
Use safe_read only in csplit.c, which has a signal handler
and where 'read' can therefore fail with EINTR.
Although safe_read also checks for oversize buffers,
that is better done via io_blksize.
* src/cat.c (simple_cat, cat):
* src/head.c (copy_fd, elide_tail_lines_pipe)
* src/tac.c (tac_seekable, copy_to_temp):
(elide_tail_lines_seekable, head_lines):
* src/tail.c (dump_remainder, file_lines, pipe_lines)
(pipe_bytes, start_bytes, start_lines, tail_forever_inotify):
* src/tr.c (plain_read):
Use plain 'read', not safe_read, since there is no
need to worry about signals or oversize requests.
Also, there is no longer a need to include safe-read.h.
* src/ioblksize.h: Include sys-limits.h, for SYS_BUFSIZE_MAX.
(io_blksize): Max out at SYS_BUFSIZE_MAX.
This commit is contained in:
Paul Eggert
2025-07-31 12:31:58 -07:00
parent 3820447667
commit d3c7072a09
6 changed files with 32 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src/cat.c
View File

@@ -37,7 +37,6 @@
#include "ioblksize.h"
#include "fadvise.h"
#include "full-write.h"
#include "safe-read.h"
#include "xbinary-io.h"
/* The official name of this program (e.g., no 'g' prefix). */
@@ -161,7 +160,7 @@ simple_cat (char *buf, idx_t bufsize)
{
/* Read a block of input. */
ptrdiff_t n_read = safe_read (input_desc, buf, bufsize);
ssize_t n_read = read (input_desc, buf, bufsize);
if (n_read < 0)
{
error (0, errno, "%s", quotef (infile));
@@ -310,7 +309,7 @@ cat (char *inbuf, idx_t insize, char *outbuf, idx_t outsize,
/* Read more input into INBUF. */
ptrdiff_t n_read = safe_read (input_desc, inbuf, insize);
ssize_t n_read = read (input_desc, inbuf, insize);
if (n_read < 0)
{
error (0, errno, "%s", quotef (infile));

15
src/head.c
View File

@@ -34,7 +34,6 @@
#include "assure.h"
#include "c-ctype.h"
#include "full-read.h"
#include "safe-read.h"
#include "stat-size.h"
#include "xbinary-io.h"
#include "xdectoint.h"
@@ -205,7 +204,7 @@ copy_fd (int src_fd, uintmax_t n_bytes)
while (0 < n_bytes)
{
idx_t n_to_read = MIN (n_bytes, sizeof buf);
ptrdiff_t n_read = safe_read (src_fd, buf, n_to_read);
ssize_t n_read = read (src_fd, buf, n_to_read);
if (n_read < 0)
return COPY_FD_READ_ERROR;
@@ -508,7 +507,7 @@ elide_tail_lines_pipe (char const *filename, int fd, uintmax_t n_elide,
LBUFFER *first, *last, *tmp;
size_t total_lines = 0; /* Total number of newlines in all buffers. */
bool ok = true;
ptrdiff_t n_read; /* Size in bytes of most recent read */
ssize_t n_read; /* Size in bytes of most recent read */
first = last = xmalloc (sizeof (LBUFFER));
first->nbytes = first->nlines = 0;
@@ -520,7 +519,7 @@ elide_tail_lines_pipe (char const *filename, int fd, uintmax_t n_elide,
n_elide newlines, or until EOF, whichever comes first. */
while (true)
{
n_read = safe_read (fd, tmp->buffer, BUFSIZ);
n_read = read (fd, tmp->buffer, BUFSIZ);
if (n_read <= 0)
break;
@@ -648,7 +647,7 @@ elide_tail_lines_seekable (char const *pretty_filename, int fd,
off_t start_pos, off_t size)
{
char buffer[BUFSIZ];
ptrdiff_t bytes_read;
ssize_t bytes_read;
off_t pos = size;
/* Set 'bytes_read' to the size of the last, probably partial, buffer;
@@ -661,7 +660,7 @@ elide_tail_lines_seekable (char const *pretty_filename, int fd,
pos -= bytes_read;
if (elseek (fd, pos, SEEK_SET, pretty_filename) < 0)
return false;
bytes_read = safe_read (fd, buffer, bytes_read);
bytes_read = read (fd, buffer, bytes_read);
if (bytes_read < 0)
{
diagnose_read_failure (pretty_filename);
@@ -730,7 +729,7 @@ elide_tail_lines_seekable (char const *pretty_filename, int fd,
if (elseek (fd, pos, SEEK_SET, pretty_filename) < 0)
return false;
bytes_read = safe_read (fd, buffer, BUFSIZ);
bytes_read = read (fd, buffer, BUFSIZ);
if (bytes_read < 0)
{
diagnose_read_failure (pretty_filename);
@@ -787,7 +786,7 @@ head_lines (char const *filename, int fd, uintmax_t lines_to_write)
while (lines_to_write)
{
ptrdiff_t bytes_read = safe_read (fd, buffer, BUFSIZ);
ssize_t bytes_read = read (fd, buffer, BUFSIZ);
idx_t bytes_to_write = 0;
if (bytes_read < 0)

7
src/ioblksize.h
View File

@@ -19,6 +19,7 @@
/* sys/stat.h and minmax.h will already have been included by system.h. */
#include <stdbit.h>
#include "stat-size.h"
#include "sys-limits.h"
/* As of Feb 2024, 256KiB is determined to be the best blksize
@@ -103,8 +104,8 @@ io_blksize (struct stat const *st)
}
}
/* Don’t go above the largest power of two that fits in idx_t and size_t,
/* Don’t go above the maximum number of bytes
to read or write in a single system call,
as that is asking for trouble. */
return MIN (MIN (IDX_MAX, SIZE_MAX) / 2 + 1,
blocksize);
return MIN (SYS_BUFSIZE_MAX, blocksize);
}

7
src/tac.c
View File

@@ -45,7 +45,6 @@ tac -r -s '.\|
#include "filenamecat.h"
#include "full-read.h"
#include "safe-read.h"
#include "temp-stream.h"
#include "xbinary-io.h"
@@ -212,7 +211,7 @@ tac_seekable (int input_fd, char const *file, off_t file_pos)
/* Scan backward, looking for end of file. This caters to proc-like
file systems where the file size is just an estimate. */
while ((saved_record_size = safe_read (input_fd, G_buffer, read_size)) == 0
while ((saved_record_size = read (input_fd, G_buffer, read_size)) == 0
&& file_pos != 0)
{
off_t rsize = read_size;
@@ -224,7 +223,7 @@ tac_seekable (int input_fd, char const *file, off_t file_pos)
/* Now scan forward, looking for end of file. */
while (saved_record_size == read_size)
{
ptrdiff_t nread = safe_read (input_fd, G_buffer, read_size);
ssize_t nread = read (input_fd, G_buffer, read_size);
if (nread == 0)
break;
saved_record_size = nread;
@@ -385,7 +384,7 @@ copy_to_temp (FILE **g_tmp, char **g_tempfile, int input_fd, char const *file)
while (true)
{
ptrdiff_t bytes_read = safe_read (input_fd, G_buffer, read_size);
ssize_t bytes_read = read (input_fd, G_buffer, read_size);
if (bytes_read == 0)
break;
if (bytes_read < 0)

30
src/tail.c
View File

@@ -445,7 +445,7 @@ dump_remainder (bool want_header, char const *prettyname, int fd,
{
char buffer[BUFSIZ];
idx_t n = n_bytes < 0 || BUFSIZ < n_remaining ? BUFSIZ : n_remaining;
ptrdiff_t bytes_read = safe_read (fd, buffer, n);
ssize_t bytes_read = read (fd, buffer, n);
if (bytes_read < 0)
{
if (errno != EAGAIN)
@@ -536,14 +536,14 @@ file_lines (char const *prettyname, int fd, struct stat const *sb,
/* Set 'bytes_read' to the size of the last, probably partial, buffer;
0 < 'bytes_read' <= 'bufsize'. */
ptrdiff_t bytes_read = (pos - start_pos) % bufsize;
if (bytes_read == 0)
bytes_read = bufsize;
idx_t bytes_to_read = (pos - start_pos) % bufsize;
if (bytes_to_read == 0)
bytes_to_read = bufsize;
/* Make 'pos' a multiple of 'bufsize' (0 if the file is short), so that all
reads will be on block boundaries, which might increase efficiency. */
pos -= bytes_read;
pos -= bytes_to_read;
xlseek (fd, pos, SEEK_SET, prettyname);
bytes_read = safe_read (fd, buffer, bytes_read);
ssize_t bytes_read = read (fd, buffer, bytes_to_read);
if (bytes_read < 0)
{
error (0, errno, _("error reading %s"), quoteaf (prettyname));
@@ -592,7 +592,7 @@ file_lines (char const *prettyname, int fd, struct stat const *sb,
pos -= bufsize;
xlseek (fd, pos, SEEK_SET, prettyname);
bytes_read = safe_read (fd, buffer, bufsize);
bytes_read = read (fd, buffer, bufsize);
if (bytes_read < 0)
{
error (0, errno, _("error reading %s"), quoteaf (prettyname));
@@ -629,7 +629,7 @@ pipe_lines (char const *prettyname, int fd, count_t n_lines,
LBUFFER *first, *last, *tmp;
idx_t total_lines = 0; /* Total number of newlines in all buffers. */
bool ok = true;
ptrdiff_t n_read; /* Size in bytes of most recent read */
ssize_t n_read; /* Size in bytes of most recent read */
first = last = xmalloc (sizeof (LBUFFER));
first->nbytes = first->nlines = 0;
@@ -639,7 +639,7 @@ pipe_lines (char const *prettyname, int fd, count_t n_lines,
/* Input is always read into a fresh buffer. */
while (true)
{
n_read = safe_read (fd, tmp->buffer, BUFSIZ);
n_read = read (fd, tmp->buffer, BUFSIZ);
if (n_read <= 0)
break;
tmp->nbytes = n_read;
@@ -768,7 +768,7 @@ pipe_bytes (char const *prettyname, int fd, count_t n_bytes,
idx_t i; /* Index into buffers. */
intmax_t total_bytes = 0; /* Total characters in all buffers. */
bool ok = true;
ptrdiff_t n_read;
ssize_t n_read;
first = last = xmalloc (sizeof (CBUFFER));
first->nbytes = 0;
@@ -778,7 +778,7 @@ pipe_bytes (char const *prettyname, int fd, count_t n_bytes,
/* Input is always read into a fresh buffer. */
while (true)
{
n_read = safe_read (fd, tmp->buffer, BUFSIZ);
n_read = read (fd, tmp->buffer, BUFSIZ);
if (n_read <= 0)
break;
*read_pos += n_read;
@@ -862,7 +862,7 @@ start_bytes (char const *prettyname, int fd, count_t n_bytes,
while (0 < n_bytes)
{
ptrdiff_t bytes_read = safe_read (fd, buffer, BUFSIZ);
ssize_t bytes_read = read (fd, buffer, BUFSIZ);
if (bytes_read == 0)
return -1;
if (bytes_read < 0)
@@ -897,7 +897,7 @@ start_lines (char const *prettyname, int fd, count_t n_lines,
while (true)
{
char buffer[BUFSIZ];
ptrdiff_t bytes_read = safe_read (fd, buffer, BUFSIZ);
ssize_t bytes_read = read (fd, buffer, BUFSIZ);
if (bytes_read == 0) /* EOF */
return -1;
if (bytes_read < 0) /* error */
@@ -1602,7 +1602,7 @@ tail_forever_inotify (int wd, struct File_spec *f, int n_files,
/* Wait for inotify events and handle them. Events on directories
ensure that watched files can be re-added when following by name.
This loop blocks on the 'safe_read' call until a new event is notified.
This loop blocks on the 'read' call until a new event is notified.
But when --pid=P is specified, tail usually waits via poll. */
ptrdiff_t len = 0;
while (true)
@@ -1663,7 +1663,7 @@ tail_forever_inotify (int wd, struct File_spec *f, int n_files,
if (pfd[1].revents)
die_pipe ();
len = safe_read (wd, evbuf, evlen);
len = read (wd, evbuf, evlen);
evbuf_off = 0;
/* For kernels prior to 2.6.21, read returns 0 when the buffer

3
src/tr.c
View File

@@ -28,7 +28,6 @@
#include "c-ctype.h"
#include "fadvise.h"
#include "quote.h"
#include "safe-read.h"
#include "xbinary-io.h"
#include "xstrtol.h"
@@ -1593,7 +1592,7 @@ squeeze_filter (char *buf, size_t size, size_t (*reader) (char *, size_t))
static size_t
plain_read (char *buf, size_t size)
{
ptrdiff_t nr = safe_read (STDIN_FILENO, buf, size);
ssize_t nr = read (STDIN_FILENO, buf, size);
if (nr < 0)
error (EXIT_FAILURE, errno, _("read error"));
return nr;