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file.c

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+/*
+ * Copyright 2008-2013 Various Authors
+ * Copyright 2005 Timo Hirvonen
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "file.h"
+#include "xmalloc.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+ssize_t read_all(int fd, void *buf, size_t count)
+{
+	char *buffer = buf;
+	ssize_t pos = 0;
+
+	do {
+		ssize_t rc;
+
+		rc = read(fd, buffer + pos, count - pos);
+		if (rc == -1) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			return -1;
+		}
+		if (rc == 0) {
+			/* eof */
+			break;
+		}
+		pos += rc;
+	} while (count - pos > 0);
+	return pos;
+}
+
+ssize_t write_all(int fd, const void *buf, size_t count)
+{
+	const char *buffer = buf;
+	int count_save = count;
+
+	do {
+		int rc;
+
+		rc = write(fd, buffer, count);
+		if (rc == -1) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			return -1;
+		}
+		buffer += rc;
+		count -= rc;
+	} while (count > 0);
+	return count_save;
+}
+
+char *mmap_file(const char *filename, ssize_t *size)
+{
+	struct stat st;
+	char *buf;
+	int fd;
+
+	fd = open(filename, O_RDONLY);
+	if (fd == -1)
+		goto err;
+
+	if (fstat(fd, &st) == -1)
+		goto close_err;
+
+	/* can't mmap empty files */
+	buf = NULL;
+	if (st.st_size) {
+		buf = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+		if (buf == MAP_FAILED)
+			goto close_err;
+	}
+
+	close(fd);
+	*size = st.st_size;
+	return buf;
+
+close_err:
+	close(fd);
+err:
+	*size = -1;
+	return NULL;
+}
+
+void buffer_for_each_line(const char *buf, int size,
+		int (*cb)(void *data, const char *line),
+		void *data)
+{
+	char *line = NULL;
+	int line_size = 0, pos = 0;
+
+	while (pos < size) {
+		int end, len;
+
+		end = pos;
+		while (end < size && buf[end] != '\n')
+			end++;
+
+		len = end - pos;
+		if (end > pos && buf[end - 1] == '\r')
+			len--;
+
+		if (len >= line_size) {
+			line_size = len + 1;
+			line = xrenew(char, line, line_size);
+		}
+		memcpy(line, buf + pos, len);
+		line[len] = 0;
+		pos = end + 1;
+
+		if (cb(data, line))
+			break;
+	}
+	free(line);
+}
+
+void buffer_for_each_line_reverse(const char *buf, int size,
+		int (*cb)(void *data, const char *line),
+		void *data)
+{
+	char *line = NULL;
+	int line_size = 0, end = size - 1;
+
+	while (end >= 0) {
+		int pos, len;
+
+		if (end > 1 && buf[end] == '\n' && buf[end - 1] == '\r')
+			end--;
+
+		pos = end;
+		while (pos > 0 && buf[pos - 1] != '\n')
+			pos--;
+
+		len = end - pos;
+		if (len >= line_size) {
+			line_size = len + 1;
+			line = xrenew(char, line, line_size);
+		}
+		memcpy(line, buf + pos, len);
+		line[len] = 0;
+		end = pos - 1;
+
+		if (cb(data, line))
+			break;
+	}
+	free(line);
+}
+
+int file_for_each_line(const char *filename,
+		int (*cb)(void *data, const char *line),
+		void *data)
+{
+	char *buf;
+	ssize_t size;
+
+	buf = mmap_file(filename, &size);
+	if (size == -1)
+		return -1;
+
+	if (buf) {
+		buffer_for_each_line(buf, size, cb, data);
+		munmap(buf, size);
+	}
+	return 0;
+}