| /* See LICENSE file for copyright and license details. */ |
| #include <sys/stat.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) |
| { |
| Rune r; |
| char *buf = NULL; |
| size_t size = 0, i = 1; |
| ssize_t len; |
| |
| if (mode == 'n') { |
| while (i < n && (len = getline(&buf, &size, fp)) > 0) |
| if (buf[len - 1] == '\n') |
| i++; |
| } else { |
| while (i < n && (len = efgetrune(&r, fp, str))) |
| i++; |
| } |
| free(buf); |
| concat(fp, str, stdout, "<stdout>"); |
| } |
| |
| static void |
| taketail(FILE *fp, const char *str, size_t n) |
| { |
| Rune *r = NULL; |
| char **ring = NULL; |
| size_t i, j, *size = NULL; |
| int seenln = 0; |
| |
| if (!n) |
| return; |
| |
| if (mode == 'n') { |
| ring = ecalloc(n, sizeof(*ring)); |
| size = ecalloc(n, sizeof(*size)); |
| |
| for (i = j = 0; getline(ring + i, size + i, fp) > 0; seenln = 1) |
| i = j = (i + 1) % n; |
| } 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]) { |
| fputs(ring[j], stdout); |
| free(ring[j]); |
| } else if (r) { |
| efputrune(&r[j], stdout, "<stdout>"); |
| } |
| } while ((j = (j + 1) % n) != i); |
| |
| free(ring); |
| free(size); |
| free(r); |
| } |
| |
| static void |
| usage(void) |
| { |
| eprintf("usage: %s [-f] [-c num | -n num | -num] [file ...]\n", argv0); |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| struct stat st1, st2; |
| FILE *fp; |
| size_t tmpsize, n = 10; |
| int fflag = 0, ret = 0, newline = 0, many = 0; |
| char *numstr, *tmp; |
| void (*tail)(FILE *, const char *, size_t) = taketail; |
| |
| ARGBEGIN { |
| case 'f': |
| fflag = 1; |
| break; |
| case 'c': |
| case 'n': |
| mode = ARGC(); |
| numstr = EARGF(usage()); |
| n = MIN(llabs(estrtonum(numstr, LLONG_MIN + 1, MIN(LLONG_MAX, SIZE_MAX))), SIZE_MAX); |
| if (strchr(numstr, '+')) |
| tail = dropinit; |
| break; |
| ARGNUM: |
| n = ARGNUMF(); |
| break; |
| default: |
| usage(); |
| } ARGEND |
| |
| if (!argc) |
| tail(stdin, "<stdin>", n); |
| 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); |
| ret = 1; |
| continue; |
| } |
| if (many) |
| printf("%s==> %s <==\n", newline ? "\n" : "", *argv); |
| if (stat(*argv, &st1) < 0) |
| eprintf("stat %s:", *argv); |
| if (!(S_ISFIFO(st1.st_mode) || S_ISREG(st1.st_mode))) |
| fflag = 0; |
| newline = 1; |
| tail(fp, *argv, n); |
| |
| if (!fflag) { |
| if (fp != stdin && fshut(fp, *argv)) |
| ret = 1; |
| 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); |
| /* 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); |
| } |
| st1 = st2; |
| } |
| sleep(1); |
| } |
| } |
| } |
| |
| ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>"); |
| |
| return ret; |
| } |