bgrep

commit be2d017c214f92a22d1f24520f841ea1180c9ab4
Author: Louis Burda <quent.burda@gmail.com>
Date:   Wed,  3 Apr 2024 01:47:43 +0200

Initial version

Diffstat:
A
.gitignore
 | 
1
+
A
LICENSE
 | 
21
+++++++++++++++++++++
A
Makefile
 | 
19
+++++++++++++++++++
A
bgrep.c
 | 
201
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

4 files changed, 242 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1 @@
+bgrep
diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Louis Burda
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/Makefile b/Makefile
@@ -0,0 +1,19 @@
+PREFIX ?= /usr/local
+BINDIR ?= /bin
+
+LDLIBS = -lpcre2-8
+
+all: bgrep
+
+clean:
+	rm -f bgrep
+
+bgrep: bgrep.c
+
+install:
+	install bgrep -t "$(DESTDIR)$(PREFIX)$(BINDIR)"
+
+uninstall:
+	rm -f "$(DESTDIR)$(PREFIX)$(BINDIR)/bgrep"
+
+.PHONY: all clean install uninstall
diff --git a/bgrep.c b/bgrep.c
@@ -0,0 +1,201 @@
+#define PCRE2_CODE_UNIT_WIDTH 8
+#include <pcre2.h>
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+static const char *marker = "\n";
+static const char *pattern = NULL;
+static bool overlap = false;
+static size_t group = 0;
+
+static void
+die(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	fputs("bgrep: ", stderr);
+	vfprintf(stderr, fmt, ap);
+	if (fmt[strlen(fmt)-1] == ':') {
+		perror(NULL);
+	} else {
+		putc('\n', stderr);
+	}
+	va_end(ap);
+
+	exit(1);
+}
+
+static void
+pcre2_die(int rc, const char *fmt, ...)
+{
+	char error_buf[256];
+	va_list ap;
+
+	pcre2_get_error_message(rc, (uint8_t *) error_buf, sizeof(error_buf));
+
+	va_start(ap, fmt);
+	fputs("bgrep: ", stderr);
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "%s\n", error_buf);
+	va_end(ap);
+
+	exit(1);
+}
+
+static void
+writeall(uint8_t *data, size_t size)
+{
+	size_t sent;
+	ssize_t n;
+
+	sent = 0;
+	while (sent != size) {
+		n = write(1, data + sent, size - sent);
+		if (n < 0) die("write:");
+		if (!n) break;
+		sent += (size_t) n;
+	}
+}
+
+static void
+writef(const char *fmt, ...)
+{
+	static void *buf = NULL;
+	static size_t bufsize = 0;
+	va_list ap;
+	va_list cpy;
+	size_t size;
+
+	va_start(ap, fmt);
+	va_copy(cpy, ap);
+	size = vsnprintf(NULL, 0, fmt, ap);
+	if (!bufsize || size + 1 > bufsize) {
+		bufsize = size + 1;
+		buf = realloc(buf, bufsize);
+		if (!buf) die("realloc:");
+	}
+	va_end(ap);
+
+	va_start(cpy, fmt);
+	vsnprintf(buf, bufsize, fmt, cpy);
+	va_end(cpy);
+	
+	writeall(buf, size);
+}
+
+void
+parse(int argc, const char **argv)
+{
+	const char **arg;
+
+	if (argc < 2) goto usage;
+
+	for (arg = argv + 1; *arg; arg++) {
+		if (!strcmp(*arg, "-h") || !strcmp(*arg, "--help")) {
+			goto usage;
+		} else if (!strcmp(*arg, "-g") || !strcmp(*arg, "--group")) {
+			group = strtoul(*++arg, NULL, 0);
+		} else if (!strcmp(*arg, "-m") || !strcmp(*arg, "--marker")) {
+			marker = *++arg;
+		} else if (!strcmp(*arg, "-o") || !strcmp(*arg, "--overlap")) {
+			overlap = true;
+		} else {
+			if (pattern) goto usage;
+			pattern = *arg;
+		}
+	}
+	return;
+
+usage:
+	fprintf(stderr, "Usage: bgrep [-g GROUP] [-m MARKER] REGEX\n");
+	exit(1);
+}
+
+int
+main(int argc, const char **argv)
+{
+	pcre2_match_data *match_data;
+	pcre2_code *regex = NULL;
+	uint8_t *match;
+	uint8_t *file;
+	size_t *ovector;
+	size_t filesize;
+	size_t filecap;
+	size_t match_size;
+	size_t error_offset = 0;
+	size_t offset;
+	size_t length;
+	size_t pos;
+	size_t lastmatch;
+	ssize_t n;
+	int rc;
+
+	parse(argc, argv);
+
+	regex = pcre2_compile((PCRE2_SPTR8)pattern, strlen(pattern),
+		PCRE2_MATCH_INVALID_UTF, &rc, &error_offset, NULL);
+	if (!regex) pcre2_die(rc, "bad regex (..'%s')", argv[argc-1] + error_offset);
+
+	match_data = pcre2_match_data_create_from_pattern(regex, NULL);
+	if (!match_data) die("pcre2_match_data_create_from_pattern");
+
+	filecap = BUFSIZ;
+	filesize = 0;
+	file = malloc(filecap);
+	if (!file) die("mallo:");
+
+	pos = 0;
+	lastmatch = 0;
+	while (true) {
+		if (BUFSIZ > filecap - filesize) {
+			filecap *= 2;
+			file = realloc(file, filecap);
+			if (!file) die("realloc:");
+		}
+
+		n = read(0, file + filesize, BUFSIZ);
+		if (n < 0) die("read:");
+		if (!n) break;
+
+		length = (size_t) n;
+		offset = 0;
+		while (offset != length) {
+			rc = pcre2_match(regex, file, filesize + length, lastmatch,
+					PCRE2_NOTEMPTY, match_data, NULL);
+			if (rc < 0 && rc != PCRE2_ERROR_NOMATCH)
+				pcre2_die(rc, "pcre2_match: ");
+
+			if (rc != PCRE2_ERROR_NOMATCH) {
+				rc = pcre2_substring_get_bynumber(match_data,
+					group, &match, &match_size);
+				if (rc) pcre2_die(rc, "pcre2_substring_get_byname: ");
+
+				ovector = pcre2_get_ovector_pointer(match_data);
+				if (overlap) {
+					lastmatch = ovector[0] + 1;
+				} else {
+					lastmatch = ovector[1];
+				}
+
+				writef("0x%zx:", filesize + ovector[0]); 
+				writeall(match, match_size);
+				writef("%s", marker); 
+			} else {
+				break;
+			}
+		}
+
+		filesize += length;
+	}
+
+	pcre2_match_data_free(match_data);
+	pcre2_code_free(regex);
+
+	return 0;
+}