Isolate sqfsdiff global state and split off option processing

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 130 insertions, 0 deletions

diff --git a/difftool/options.c b/difftool/options.c
new file mode 100644
index 0000000..8224b1d
--- /dev/null
+++ b/difftool/options.c
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * sqfsdiff.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "sqfsdiff.h"
+
+static struct option long_opts[] = {
+	{ "old", required_argument, NULL, 'a' },
+	{ "new", required_argument, NULL, 'b' },
+	{ "no-owner", no_argument, NULL, 'O' },
+	{ "no-permissions", no_argument, NULL, 'P' },
+	{ "no-contents", no_argument, NULL, 'C' },
+	{ "timestamps", no_argument, NULL, 'T' },
+	{ "inode-num", no_argument, NULL, 'I' },
+	{ "super", no_argument, NULL, 'S' },
+	{ "extract", required_argument, NULL, 'e' },
+	{ "help", no_argument, NULL, 'h' },
+	{ "version", no_argument, NULL, 'V' },
+};
+
+static const char *short_opts = "a:b:OPCTISe:hV";
+
+static const char *usagestr =
+"Usage: sqfsdiff [OPTIONS...] --old,-a <first> --new,-b <second>\n"
+"\n"
+"Compare two squashfs images. In contrast to doing a direct diff of the\n"
+"images, this actually parses the filesystems and generates a more\n"
+"meaningful difference report.\n"
+"\n"
+"If only contents are compared, any differences in packed file layout,\n"
+"ordering, compression, inode allocation and so on is ignored and the two\n"
+"images are considered equal if each directory contains the same entries,\n"
+"symlink with the same paths have the same targets, device nodes the same\n"
+"device number and files the same size and contents.\n"
+"\n"
+"A report of any difference is printed to stdout. The exit status is similar\n"
+"that of diff(1): 0 means equal, 1 means different, 2 means problem.\n"
+"\n"
+"Possible options:\n"
+"\n"
+"  --old, -a <first>           The first of the two images to compare.\n"
+"  --new, -b <second>          The second of the two images to compare.\n"
+"\n"
+"  --no-contents, -C           Do not compare file contents.\n"
+"  --no-owner, -O              Do not compare file owners.\n"
+"  --no-permissions, -P        Do not compare permission bits.\n"
+"\n"
+"  --timestamps, -T            Compare file timestamps.\n"
+"  --inode-num, -I             Compare inode numbers of all files.\n"
+"  --super, -S                 Also compare metadata in super blocks.\n"
+"\n"
+"  --extract, -e <path>        Extract files that differ to the specified\n"
+"                              directory. Contents of the first image end up\n"
+"                              in a subdirectory 'a' and of the second image\n"
+"                              in a subdirectory 'b'.\n"
+"\n"
+"  --help, -h                  Print help text and exit.\n"
+"  --version, -V               Print version information and exit.\n"
+"\n";
+
+void process_options(sqfsdiff_t *sd, int argc, char **argv)
+{
+	int i;
+
+	for (;;) {
+		i = getopt_long(argc, argv, short_opts, long_opts, NULL);
+		if (i == -1)
+			break;
+
+		switch (i) {
+		case 'a':
+			sd->old_path = optarg;
+			break;
+		case 'b':
+			sd->new_path = optarg;
+			break;
+		case 'O':
+			sd->compare_flags |= COMPARE_NO_OWNER;
+			break;
+		case 'P':
+			sd->compare_flags |= COMPARE_NO_PERM;
+			break;
+		case 'C':
+			sd->compare_flags |= COMPARE_NO_CONTENTS;
+			break;
+		case 'T':
+			sd->compare_flags |= COMPARE_TIMESTAMP;
+			break;
+		case 'I':
+			sd->compare_flags |= COMPARE_INODE_NUM;
+			break;
+		case 'S':
+			sd->compare_super = true;
+			break;
+		case 'e':
+			sd->compare_flags |= COMPARE_EXTRACT_FILES;
+			sd->extract_dir = optarg;
+			break;
+		case 'h':
+			fputs(usagestr, stdout);
+			exit(EXIT_SUCCESS);
+		case 'V':
+			print_version();
+			exit(EXIT_SUCCESS);
+		default:
+			goto fail_arg;
+		}
+	}
+
+	if (sd->old_path == NULL) {
+		fputs("Missing arguments: first filesystem\n", stderr);
+		goto fail_arg;
+	}
+
+	if (sd->new_path == NULL) {
+		fputs("Missing arguments: second filesystem\n", stderr);
+		goto fail_arg;
+	}
+
+	if (optind < argc) {
+		fputs("Unknown extra arguments\n", stderr);
+		goto fail_arg;
+	}
+	return;
+fail_arg:
+	fprintf(stderr, "Try `sqfsdiff --help' for more information.\n");
+	exit(EXIT_FAILURE);
+}