commit 3276fbea1cfb23ed5eeb11aa18813c461acca004
parent 9a3b12525bd3a2627f5a45c7afe00737a041bb5b
Author: Michael Forney <mforney@mforney.org>
Date: Mon, 3 Jul 2017 14:58:49 -0700
concat: Use plain read/write instead of buffered stdio
If we are just copying data from one file to another, we don't need to
fill a complete buffer, just read a chunk at a time, and write it to the
output.
Diffstat:
| M | cat.c | | | 39 | +++++++++++++++------------------------ |
| M | libutil/concat.c | | | 24 | ++++++++++++++---------- |
| M | libutil/cp.c | | | 49 | ++++++++++++++++++++----------------------------- |
| M | sponge.c | | | 31 | +++++++++++++++++-------------- |
| M | tail.c | | | 199 | ++++++++++++++++++++++++++++++++++++++++++++++++------------------------------- |
| M | text.h | | | 1 | - |
| M | util.h | | | 1 | + |
| M | xinstall.c | | | 25 | ++++++++++++------------- |
8 files changed, 200 insertions(+), 169 deletions(-)
diff --git a/cat.c b/cat.c
@@ -1,22 +1,11 @@
/* See LICENSE file for copyright and license details. */
-#include <stdio.h>
+#include <fcntl.h>
#include <string.h>
#include <unistd.h>
-#include "text.h"
#include "util.h"
static void
-uconcat(FILE *fp1, const char *s1, FILE *fp2, const char *s2)
-{
- int c;
-
- setbuf(fp2, NULL);
- while ((c = getc(fp1)) != EOF)
- putc(c, fp2);
-}
-
-static void
usage(void)
{
eprintf("usage: %s [-u] [file ...]\n", argv0);
@@ -25,37 +14,39 @@ usage(void)
int
main(int argc, char *argv[])
{
- FILE *fp;
- int ret = 0;
- void (*cat)(FILE *, const char *, FILE *, const char *) = &concat;
+ int fd, ret = 0;
ARGBEGIN {
case 'u':
- cat = &uconcat;
break;
default:
usage();
} ARGEND
if (!argc) {
- cat(stdin, "<stdin>", stdout, "<stdout>");
+ if (concat(0, "<stdin>", 1, "<stdout>") < 0)
+ ret = 1;
} else {
for (; *argv; argc--, argv++) {
if (!strcmp(*argv, "-")) {
*argv = "<stdin>";
- fp = stdin;
- } else if (!(fp = fopen(*argv, "r"))) {
- weprintf("fopen %s:", *argv);
+ fd = 0;
+ } else if ((fd = open(*argv, O_RDONLY)) < 0) {
+ weprintf("open %s:", *argv);
ret = 1;
continue;
}
- cat(fp, *argv, stdout, "<stdout>");
- if (fp != stdin && fshut(fp, *argv))
+ switch (concat(fd, *argv, 1, "<stdout>")) {
+ case -1:
ret = 1;
+ break;
+ case -2:
+ return 1; /* exit on write error */
+ }
+ if (fd != 0)
+ close(fd);
}
}
- ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>");
-
return ret;
}
diff --git a/libutil/concat.c b/libutil/concat.c
@@ -1,19 +1,23 @@
/* See LICENSE file for copyright and license details. */
-#include <stdio.h>
+#include <unistd.h>
-#include "../text.h"
#include "../util.h"
-void
-concat(FILE *fp1, const char *s1, FILE *fp2, const char *s2)
+int
+concat(int f1, const char *s1, int f2, const char *s2)
{
char buf[BUFSIZ];
- size_t n;
+ ssize_t n;
- while ((n = fread(buf, 1, sizeof(buf), fp1))) {
- fwrite(buf, 1, n, fp2);
-
- if (feof(fp1) || ferror(fp1) || ferror(fp2))
- break;
+ while ((n = read(f1, buf, sizeof(buf))) > 0) {
+ if (writeall(f2, buf, n) < 0) {
+ weprintf("write %s:", s2);
+ return -2;
+ }
+ }
+ if (n < 0) {
+ weprintf("read %s:", s1);
+ return -1;
}
+ return 0;
}
diff --git a/libutil/cp.c b/libutil/cp.c
@@ -12,7 +12,6 @@
#include <utime.h>
#include "../fs.h"
-#include "../text.h"
#include "../util.h"
int cp_aflag = 0;
@@ -27,7 +26,7 @@ int
cp(const char *s1, const char *s2, int depth)
{
DIR *dp;
- FILE *f1, *f2;
+ int f1, f2;
struct dirent *d;
struct stat st;
struct timespec times[2];
@@ -113,46 +112,38 @@ cp(const char *s1, const char *s2, int depth)
return 0;
}
} else {
- if (!(f1 = fopen(s1, "r"))) {
- weprintf("fopen %s:", s1);
+ if ((f1 = open(s1, O_RDONLY)) < 0) {
+ weprintf("open %s:", s1);
cp_status = 1;
return 0;
}
- if (!(f2 = fopen(s2, "w"))) {
- if (cp_fflag) {
- if (unlink(s2) < 0 && errno != ENOENT) {
- weprintf("unlink %s:", s2);
- cp_status = 1;
- fclose(f1);
- return 0;
- } else if (!(f2 = fopen(s2, "w"))) {
- weprintf("fopen %s:", s2);
- cp_status = 1;
- fclose(f1);
- return 0;
- }
- } else {
- weprintf("fopen %s:", s2);
+ if ((f2 = creat(s2, st.st_mode)) < 0 && cp_fflag) {
+ if (unlink(s2) < 0 && errno != ENOENT) {
+ weprintf("unlink %s:", s2);
cp_status = 1;
- fclose(f1);
+ close(f1);
return 0;
}
+ f2 = creat(s2, st.st_mode);
}
- concat(f1, s1, f2, s2);
-
- /* preserve permissions by default */
- fchmod(fileno(f2), st.st_mode);
-
- if (fclose(f2) == EOF) {
- weprintf("fclose %s:", s2);
+ if (f2 < 0) {
+ weprintf("creat %s:", s2);
cp_status = 1;
+ close(f1);
return 0;
}
- if (fclose(f1) == EOF) {
- weprintf("fclose %s:", s1);
+ if (concat(f1, s1, f2, s2) < 0) {
cp_status = 1;
+ close(f1);
+ close(f2);
return 0;
}
+
+ /* preserve permissions by default */
+ fchmod(f2, st.st_mode);
+
+ close(f1);
+ close(f2);
}
if (cp_aflag || cp_pflag) {
diff --git a/sponge.c b/sponge.c
@@ -1,7 +1,8 @@
/* See LICENSE file for copyright and license details. */
-#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
-#include "text.h"
#include "util.h"
static void
@@ -13,24 +14,26 @@ usage(void)
int
main(int argc, char *argv[])
{
- FILE *fp, *tmpfp;
- int ret = 0;
+ char tmp[] = "/tmp/sponge-XXXXXX";
+ int fd, tmpfd;
argv0 = argv[0], argc--, argv++;
if (argc != 1)
usage();
- if (!(tmpfp = tmpfile()))
- eprintf("tmpfile:");
- concat(stdin, "<stdin>", tmpfp, "<tmpfile>");
- rewind(tmpfp);
+ if ((tmpfd = mkstemp(tmp)) < 0)
+ eprintf("mkstemp:");
+ unlink(tmp);
+ if (concat(0, "<stdin>", tmpfd, "<tmpfile>") < 0)
+ return 1;
+ if (lseek(tmpfd, 0, SEEK_SET) < 0)
+ eprintf("lseek:");
- if (!(fp = fopen(argv[0], "w")))
- eprintf("fopen %s:", argv[0]);
- concat(tmpfp, "<tmpfile>", fp, argv[0]);
+ if ((fd = creat(argv[0], 0666)) < 0)
+ eprintf("creat %s:", argv[0]);
+ if (concat(tmpfd, "<tmpfile>", fd, argv[0]) < 0)
+ return 1;
- ret |= fshut(fp, argv[0]) | fshut(tmpfp, "<tmpfile>");
-
- return ret;
+ return 0;
}
diff --git a/tail.c b/tail.c
@@ -1,80 +1,125 @@
/* See LICENSE file for copyright and license details. */
#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
-#include "text.h"
#include "utf.h"
#include "util.h"
static char mode = 'n';
-static void
-dropinit(FILE *fp, const char *str, size_t n)
+static int
+dropinit(int fd, const char *fname, size_t count)
{
Rune r;
- char *buf = NULL;
- size_t size = 0, i = 1;
- ssize_t len;
+ char buf[BUFSIZ], *p;
+ ssize_t n;
+ int nr;
+
+ if (count < 2)
+ goto copy;
+ count--; /* numbering starts at 1 */
+ while (count && (n = read(fd, buf, sizeof(buf))) > 0) {
+ if (mode == 'n') {
+ for (p = buf; count && n > 0; p++, n--) {
+ if (*p == '\n')
+ count--;
+ }
+ } else {
+ for (p = buf; count && n > 0; p += nr, n -= nr, count--) {
+ nr = charntorune(&r, p, n);
+ if (!nr) {
+ /* we don't have a full rune, move
+ * remaining data to beginning and read
+ * again */
+ memmove(buf, p, n);
+ break;
+ }
+ }
+ }
+ }
+ if (count) {
+ if (n < 0)
+ weprintf("read %s:", fname);
+ if (n <= 0)
+ return n;
+ }
- if (mode == 'n') {
- while (i < n && (len = getline(&buf, &size, fp)) > 0)
- if (len > 0 && buf[len - 1] == '\n')
- i++;
- } else {
- while (i < n && efgetrune(&r, fp, str))
- i++;
+ /* write the rest of the buffer */
+ if (writeall(1, p, n) < 0)
+ eprintf("write:");
+copy:
+ switch (concat(fd, fname, 1, "<stdout>")) {
+ case -1: /* read error */
+ return -1;
+ case -2: /* write error */
+ exit(1);
+ default:
+ return 0;
}
- free(buf);
- concat(fp, str, stdout, "<stdout>");
}
-static void
-taketail(FILE *fp, const char *str, size_t n)
+static int
+taketail(int fd, const char *fname, size_t count)
{
- Rune *r = NULL;
- struct line *ring = NULL;
- size_t i, j, *size = NULL;
- ssize_t len;
- int seenln = 0;
-
- if (!n)
- return;
-
- if (mode == 'n') {
- ring = ecalloc(n, sizeof(*ring));
- size = ecalloc(n, sizeof(*size));
-
- for (i = j = 0; (len = getline(&ring[i].data,
- &size[i], fp)) > 0; seenln = 1) {
- ring[i].len = len;
- i = j = (i + 1) % n;
+ static char *buf = NULL;
+ static size_t size = 0;
+ char *p;
+ size_t len = 0, left;
+ ssize_t n;
+
+ if (!count)
+ return 0;
+ for (;;) {
+ if (len + BUFSIZ > size) {
+ /* make sure we have at least BUFSIZ to read */
+ size += 2 * BUFSIZ;
+ buf = erealloc(buf, size);
}
- } else {
- r = ecalloc(n, sizeof(*r));
-
- for (i = j = 0; efgetrune(&r[i], fp, str); )
- i = j = (i + 1) % n;
- }
- if (ferror(fp))
- eprintf("%s: read error:", str);
-
- do {
- if (seenln && ring && ring[j].data) {
- fwrite(ring[j].data, 1, ring[j].len, stdout);
- free(ring[j].data);
- } else if (r) {
- efputrune(&r[j], stdout, "<stdout>");
+ n = read(fd, buf + len, size - len);
+ if (n < 0) {
+ weprintf("read %s:", fname);
+ return -1;
}
- } while ((j = (j + 1) % n) != i);
-
- free(ring);
- free(size);
- free(r);
+ if (n == 0)
+ break;
+ len += n;
+ if (mode == 'n') {
+ /* ignore the last character; if it is a newline, it
+ * ends the last line */
+ for (p = buf + len - 2, left = count; p >= buf; p--) {
+ if (*p != '\n')
+ continue;
+ left--;
+ if (!left) {
+ p++;
+ break;
+ }
+ }
+ } else {
+ for (p = buf + len - 1, left = count; p >= buf; p--) {
+ /* skip utf-8 continuation bytes */
+ if ((*p & 0xc0) == 0x80)
+ continue;
+ left--;
+ if (!left)
+ break;
+ }
+ }
+ if (p > buf) {
+ len -= p - buf;
+ memmove(buf, p, len);
+ }
+ }
+ if (writeall(1, buf, len) < 0)
+ eprintf("write:");
+ return 0;
}
static void
@@ -87,11 +132,11 @@ int
main(int argc, char *argv[])
{
struct stat st1, st2;
- FILE *fp;
- size_t tmpsize, n = 10;
+ int fd;
+ size_t n = 10;
int fflag = 0, ret = 0, newline = 0, many = 0;
- char *numstr, *tmp;
- void (*tail)(FILE *, const char *, size_t) = taketail;
+ char *numstr;
+ int (*tail)(int, const char *, size_t) = taketail;
ARGBEGIN {
case 'f':
@@ -113,17 +158,18 @@ main(int argc, char *argv[])
usage();
} ARGEND
- if (!argc)
- tail(stdin, "<stdin>", n);
- else {
+ if (!argc) {
+ if (tail(0, "<stdin>", n) < 0)
+ ret = 1;
+ } else {
if ((many = argc > 1) && fflag)
usage();
for (newline = 0; *argv; argc--, argv++) {
if (!strcmp(*argv, "-")) {
*argv = "<stdin>";
- fp = stdin;
- } else if (!(fp = fopen(*argv, "r"))) {
- weprintf("fopen %s:", *argv);
+ fd = 0;
+ } else if ((fd = open(*argv, O_RDONLY)) < 0) {
+ weprintf("open %s:", *argv);
ret = 1;
continue;
}
@@ -134,27 +180,26 @@ main(int argc, char *argv[])
if (!(S_ISFIFO(st1.st_mode) || S_ISREG(st1.st_mode)))
fflag = 0;
newline = 1;
- tail(fp, *argv, n);
+ if (tail(fd, *argv, n) < 0) {
+ ret = 1;
+ fflag = 0;
+ }
if (!fflag) {
- if (fp != stdin && fshut(fp, *argv))
- ret = 1;
+ if (fd != 0)
+ close(fd);
continue;
}
- for (tmp = NULL, tmpsize = 0;;) {
- while (getline(&tmp, &tmpsize, fp) > 0) {
- fputs(tmp, stdout);
- fflush(stdout);
- }
- if (ferror(fp))
- eprintf("readline %s:", *argv);
- clearerr(fp);
+ for (;;) {
+ if (concat(fd, *argv, 1, "<stdout>") < 0)
+ exit(1);
/* ignore error in case file was removed, we continue
* tracking the existing open file descriptor */
if (!stat(*argv, &st2)) {
if (st2.st_size < st1.st_size) {
fprintf(stderr, "%s: file truncated\n", *argv);
- rewind(fp);
+ if (lseek(fd, SEEK_SET, 0) < 0)
+ eprintf("lseek:");
}
st1 = st2;
}
@@ -163,7 +208,5 @@ main(int argc, char *argv[])
}
}
- ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>");
-
return ret;
}
diff --git a/text.h b/text.h
@@ -13,5 +13,4 @@ struct linebuf {
#define EMPTY_LINEBUF {NULL, 0, 0,}
void getlines(FILE *, struct linebuf *);
-void concat(FILE *, const char *, FILE *, const char *);
int linecmp(struct line *, struct line *);
diff --git a/util.h b/util.h
@@ -64,6 +64,7 @@ int eregcomp(regex_t *, const char *, int);
/* io */
ssize_t writeall(int, const void *, size_t);
+int concat(int, const char *, int, const char *);
/* misc */
void enmasse(int, char **, int (*)(const char *, const char *, int));
diff --git a/xinstall.c b/xinstall.c
@@ -2,6 +2,7 @@
#include <grp.h>
#include <pwd.h>
#include <errno.h>
+#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
@@ -10,7 +11,6 @@
#include <sys/wait.h>
#include "util.h"
-#include "text.h"
static int Dflag = 0;
static gid_t group;
@@ -44,7 +44,7 @@ static int
install(const char *s1, const char *s2, int depth)
{
DIR *dp;
- FILE *f1, *f2;
+ int f1, f2;
struct dirent *d;
struct stat st;
ssize_t r;
@@ -92,23 +92,22 @@ install(const char *s1, const char *s2, int depth)
else if (mknod(s2, (st.st_mode & ~07777) | mode, st.st_rdev) < 0)
eprintf("mknod %s:", s2);
} else {
- if (!(f1 = fopen(s1, "r")))
- eprintf("fopen %s:", s1);
- if (!(f2 = fopen(s2, "w"))) {
+ if ((f1 = open(s1, O_RDONLY)) < 0)
+ eprintf("open %s:", s1);
+ if ((f2 = creat(s2, 0600)) < 0) {
if (unlink(s2) < 0 && errno != ENOENT)
eprintf("unlink %s:", s2);
- else if (!(f2 = fopen(s2, "w")))
- eprintf("fopen %s:", s2);
+ if ((f2 = creat(s2, 0600)) < 0)
+ eprintf("creat %s:", s2);
}
- concat(f1, s1, f2, s2);
+ if (concat(f1, s1, f2, s2) < 0)
+ exit(1);
- if (fchmod(fileno(f2), mode) < 0)
+ if (fchmod(f2, mode) < 0)
eprintf("fchmod %s:", s2);
- if (fclose(f2) == EOF)
- eprintf("fclose %s:", s2);
- if (fclose(f1) == EOF)
- eprintf("fclose %s:", s1);
+ close(f1);
+ close(f2);
}
if (lchown(s2, owner, group) < 0)
