160 lines
3.0 KiB
C
160 lines
3.0 KiB
C
/* See LICENSE file for copyright and license details. */
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#include <sys/stat.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "text.h"
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#include "utf.h"
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#include "util.h"
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static int fflag = 0;
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static size_t num = 10;
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static char mode = 'n';
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static void
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dropinit(FILE *fp, const char *str)
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{
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Rune r;
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char *buf = NULL;
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size_t size = 0, i = 0;
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ssize_t len;
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if (mode == 'n') {
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while (i < num && (len = getline(&buf, &size, fp)) > 0)
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if (len > 0 && buf[len - 1] == '\n')
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i++;
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} else {
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while (i < num && (len = efgetrune(&r, fp, str)))
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i++;
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}
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free(buf);
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concat(fp, str, stdout, "<stdout>");
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}
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static void
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taketail(FILE *fp, const char *str)
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{
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Rune *r = NULL;
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char **ring = NULL;
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size_t i, j, *size = NULL;
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if (mode == 'n') {
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ring = ecalloc(num, sizeof *ring);
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size = ecalloc(num, sizeof *size);
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for (i = j = 0; getline(&ring[i], &size[i], fp) > 0; )
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i = j = (i + 1) % num;
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} else {
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r = ecalloc(num, sizeof *r);
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for (i = j = 0; efgetrune(&r[i], fp, str); )
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i = j = (i + 1) % num;
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}
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if (ferror(fp))
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eprintf("%s: read error:", str);
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do {
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if (ring && ring[j]) {
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fputs(ring[j], stdout);
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free(ring[j]);
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} else if (r) {
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efputrune(&r[j], stdout, "<stdout>");
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}
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} while ((j = (j + 1) % num) != i);
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free(ring);
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free(size);
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free(r);
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}
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static void
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usage(void)
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{
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eprintf("usage: %s [-f] [-c num | -n num | -num] [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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struct stat st1, st2;
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FILE *fp;
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size_t tmpsize;
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int ret = 0, newline, many;
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char *numstr, *tmp;
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void (*tail)(FILE *, const char *) = taketail;
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ARGBEGIN {
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case 'f':
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fflag = 1;
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break;
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case 'c':
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case 'n':
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mode = ARGC();
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numstr = EARGF(usage());
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num = MIN(llabs(estrtonum(numstr, LLONG_MIN + 1, MIN(LLONG_MAX, SIZE_MAX))), SIZE_MAX);
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if (strchr(numstr, '+'))
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tail = dropinit;
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break;
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ARGNUM:
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num = ARGNUMF();
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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 (!num)
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return 0;
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if (!argc)
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tail(stdin, "<stdin>");
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else {
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if ((many = argc > 1) && fflag)
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usage();
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for (newline = 0; *argv; argc--, argv++) {
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if (!(fp = fopen(*argv, "r"))) {
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weprintf("fopen %s:", *argv);
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ret = 1;
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continue;
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}
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if (many)
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printf("%s==> %s <==\n", newline ? "\n" : "", *argv);
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if (stat(*argv, &st1) < 0)
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eprintf("stat %s:", *argv);
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if (!(S_ISFIFO(st1.st_mode) || S_ISREG(st1.st_mode)))
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fflag = 0;
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newline = 1;
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tail(fp, *argv);
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if (!fflag) {
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fclose(fp);
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continue;
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}
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for (tmp = NULL, tmpsize = 0;;) {
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while (getline(&tmp, &tmpsize, fp) > 0) {
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fputs(tmp, stdout);
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fflush(stdout);
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}
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if (ferror(fp))
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eprintf("readline %s:", *argv);
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clearerr(fp);
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/* ignore error in case file was removed, we continue
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* tracking the existing open file descriptor */
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if (!stat(*argv, &st2)) {
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if (st2.st_size < st1.st_size) {
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fprintf(stderr, "%s: file truncated\n", *argv);
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rewind(fp);
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}
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st1 = st2;
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}
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sleep(1);
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}
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}
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}
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return ret;
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}
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