9a3b12525b
fread reads the entire requested size (BUFSIZ), which causes tools to block if only small amounts of data are available at a time. At best, this causes unnecessary copies and inefficiency, at worst, tools like tee and cat are almost unusable in some cases since they only display large chunks of data at a time.
61 lines
1.0 KiB
C
61 lines
1.0 KiB
C
/* See LICENSE file for copyright and license details. */
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#include <fcntl.h>
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#include <signal.h>
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#include <unistd.h>
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#include "util.h"
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static void
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usage(void)
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{
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eprintf("usage: %s [-ai] [file ...]\n", argv0);
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}
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int
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main(int argc, char *argv[])
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{
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int *fds = NULL;
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size_t i, nfds;
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ssize_t n;
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int ret = 0, aflag = O_TRUNC, iflag = 0;
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char buf[BUFSIZ];
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ARGBEGIN {
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case 'a':
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aflag = O_APPEND;
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break;
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case 'i':
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iflag = 1;
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break;
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default:
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usage();
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} ARGEND
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if (iflag && signal(SIGINT, SIG_IGN) == SIG_ERR)
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eprintf("signal:");
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nfds = argc + 1;
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fds = ecalloc(nfds, sizeof(*fds));
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for (i = 0; i < argc; i++) {
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if ((fds[i] = open(argv[i], O_WRONLY|O_CREAT|aflag, 0666)) < 0) {
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weprintf("open %s:", argv[i]);
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ret = 1;
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}
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}
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fds[i] = 1;
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while ((n = read(0, buf, sizeof(buf))) > 0) {
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for (i = 0; i < nfds; i++) {
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if (fds[i] >= 0 && writeall(fds[i], buf, n) < 0) {
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weprintf("write %s:", (i != argc) ? argv[i] : "<stdout>");
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fds[i] = -1;
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ret = 1;
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}
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}
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}
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if (n < 0)
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eprintf("read <stdin>:");
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return ret;
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}
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