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| -rw-r--r-- | fsub.c | 181 |
1 files changed, 181 insertions, 0 deletions
@@ -0,0 +1,181 @@ +/* + * BSD Zero Clause License + * + * Copyright (c) 2023 Thomas Voss + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR + * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +#define PCRE2_CODE_UNIT_WIDTH 8 +#define _POSIX_C_SOURCE 200809L + +#include <sys/mman.h> +#include <sys/stat.h> + +#include <err.h> +#include <fcntl.h> +#include <getopt.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <pcre2.h> + +#define die(...) err(EXIT_FAILURE, __VA_ARGS__) +#define streq(a, b) (strcmp(a, b) == 0) + +int rv = EXIT_SUCCESS; +const char *argv0; +static PCRE2_UCHAR errbuf[256]; + +static int loadfile(char **, char *); +static char *stdio_to_string(void); +static void fsub(char *, pcre2_match_data *, pcre2_code *, char *); + +int +main(int argc, char *argv[]) +{ + int fd, fd2, ec, opt; + char *needle, *haystack, *repl, + *argv0 = argv[0], + *optstr = "dim", + *progargs = "[-dim] pattern file [file ...]"; + uint32_t rx_opts = PCRE2_UTF; + pcre2_code *rx; + pcre2_match_data *mdata; + PCRE2_SIZE eo; + static struct option longopts[] = { + {"dotall", no_argument, NULL, 'd'}, + {"ignore-case", no_argument, NULL, 'i'}, + {"multiline", no_argument, NULL, 'm'}, + { NULL, 0, NULL, 0 } + }; + + argv0 = argv[0]; + while ((opt = getopt_long(argc, argv, optstr, longopts, NULL)) != -1) { + switch (opt) { + case 'd': + rx_opts |= PCRE2_DOTALL; + break; + case 'i': + rx_opts |= PCRE2_CASELESS; + break; + case 'm': + rx_opts |= PCRE2_MULTILINE; + break; + default: + fprintf(stderr, "Usage: %s %s\n", argv0, progargs); + exit(EXIT_FAILURE); + } + } + + argc -= optind; + argv += optind; + + if (argc < 2) { + fprintf(stderr, "Usage: %s %s\n", argv0, progargs); + exit(EXIT_FAILURE); + } + + needle = argv[0]; + fd = loadfile(&repl, argv[1]); + rx = pcre2_compile((PCRE2_SPTR) needle, PCRE2_ZERO_TERMINATED, + rx_opts, &ec, &eo, NULL); + if (rx == NULL) { + pcre2_get_error_message(ec, errbuf, sizeof(errbuf)); + fprintf(stderr, + "%s: Regex compilation failed at offset %d: %s\n", + argv[0], (int) eo, errbuf); + exit(EXIT_FAILURE); + } + mdata = pcre2_match_data_create_from_pattern(rx, NULL); + + for (int i = 2; i < argc; i++) { + if (streq(argv[i], "-")) { + haystack = stdio_to_string(); + fsub(haystack, mdata, rx, repl); + free(haystack); + } else { + fd2 = loadfile(&haystack, argv[i]); + fsub(haystack, mdata, rx, repl); + close(fd2); + } + } + + pcre2_match_data_free(mdata); + pcre2_code_free(rx); + close(fd); + + return rv; +} + +int +loadfile(char **s, char *filename) +{ + int fd; + struct stat sb; + + if ((fd = open(filename, O_RDONLY)) == -1) + die("open: %s", filename); + if (fstat(fd, &sb) == -1) + die("fstat: %s", filename); + *s = mmap(0, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0); + if (*s == MAP_FAILED) + die("mmap: %s", filename); + return fd; +} + +char * +stdio_to_string(void) +{ + char *buf = NULL; + size_t bs = 0; + + getdelim(&buf, &bs, EOF, stdin); + + return buf; +} + +void +fsub(char *haystack, pcre2_match_data *mdata, pcre2_code *rx, char *repl) +{ + int rc; + size_t pos = 0; + PCRE2_SPTR haystack_start = (PCRE2_SPTR) haystack; + PCRE2_SIZE *ovec; + (void) repl; + + do { + rc = pcre2_match(rx, haystack_start, PCRE2_ZERO_TERMINATED, pos, + 0, mdata, NULL); + if (rc == PCRE2_ERROR_NOMATCH) { + if (pos == 0) + rv = EXIT_FAILURE; + break; + } + if (rc < 0) { + fprintf(stderr, + "%s: pcre2_match() failed with code %d\n", + argv0, rc); + pcre2_match_data_free(mdata); + pcre2_code_free(rx); + exit(EXIT_FAILURE); + } + ovec = pcre2_get_ovector_pointer(mdata); + printf("%.*s%s", (int) (ovec[0] - pos), haystack_start + pos, + repl); + pos = ovec[1]; + } while (rc >= 0); + fputs((char *) haystack_start + pos, stdout); +} |