Preparation for implementing set/delete operations.

* src/backup.c: New file.
* gnulib.modules: Request backupfile, dirname and save-cwd.
* src/Makefile.am (idest_SOURCES): Add backup.c
* src/cmdline.opt: New options --backup and --backup-directory.
* src/id3v2.c: Minor change.
* src/idest.h: Include backupfile.h
(backup_type, backup_dir): New externs.
* src/main.c: Minor change.

7 files changed, 257 insertions, 6 deletions

diff --git a/gnulib.modules b/gnulib.modules
index 3487fe9..4296821 100644
--- a/gnulib.modules
+++ b/gnulib.modules
@@ -2,9 +2,12 @@
 # A module name per line. Empty lines and comments are ignored.
 
 argmatch
+backupfile
+dirname
 getopt
 gitlog-to-changelog
 error
 linked-list
 progname
+save-cwd
 xalloc
diff --git a/src/Makefile.am b/src/Makefile.am
index 6f8066a..212e454 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -16,6 +16,7 @@
 
 bin_PROGRAMS=idest
 idest_SOURCES=\
+ backup.c\
  idest.h\
  id3v1.c\
  id3v1.h\
diff --git a/src/backup.c b/src/backup.c
new file mode 100644
index 0000000..495d6ac
--- /dev/null
+++ b/src/backup.c
@@ -0,0 +1,220 @@
+/* This file is part of Idest.
+   Copyright (C) 2009 Sergey Poznyakoff
+ 
+   Idest 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 3, or (at your option)
+   any later version.
+ 
+   Idest 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 Idest.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include "idest.h"
+#include <sys/stat.h>
+#include <fcntl.h>
+#include "save-cwd.h"
+#include "dirname.h"
+#include "backupfile.h"
+
+#define MKDIR_PERMISSIONS 0777
+#define CREAT_PERMISSIONS 0666
+
+/* Concatenate BASE directory name, a single directory separator (/) and
+   NAME. Return in PBASELEN the length of BASE, not counting eventual trailing
+   slash. */
+char *
+concat_dir(const char *base, const char *name, size_t *pbaselen)
+{
+	size_t len = strlen(base);
+	size_t size;
+	char *dir;
+
+	while (len > 0 && base[len - 1] == '/')
+		len--;
+
+	size = len + 1 + strlen(name);
+	dir = xmalloc(size + 1);
+	memcpy(dir, base, len);
+	dir[len++] = '/';
+	strcpy(dir + len, name);
+
+	if (pbaselen)
+		*pbaselen = len;
+	return dir;
+}
+
+/* Create the directory DIR, eventually creating all intermediate directories
+   starting from DIR + BASELEN. */
+int
+create_hierarchy(char *dir, size_t baselen)
+{
+	int rc;
+	struct stat st;
+	char *p;
+
+	if (stat(dir, &st) == 0) {
+		if (!S_ISDIR(st.st_mode)) {
+			error(0, 0, "component %s is not a directory", dir);
+			return 1;
+		}
+		return 0;
+	} else if (errno != ENOENT) {
+		error(0, errno, "cannot stat file %s", dir);
+		return 1;
+	}
+
+	p = strrchr(dir, '/');
+	if (p) {
+		if (p - dir + 1 < baselen) {
+			error(0, 0, "base directory %s does not exist", dir);
+			return 1;
+		}
+		*p = 0;
+	}
+
+	rc = create_hierarchy(dir, baselen);
+	if (rc == 0) {
+		if (p)
+			*p = '/';
+		if (mkdir(dir, MKDIR_PERMISSIONS)) {
+			error(0, errno, "cannot create directory %s", dir);
+			rc = 1;
+		}
+	}
+	return rc;
+}
+
+/* Create a directory BASE/NAME (with eventual intermediate directories in
+   NAME).  */
+char *
+create_directory(const char *base, const char *name)
+{
+	size_t baselen;
+	char *dir = concat_dir(base, name, &baselen);
+
+	if (create_hierarchy(dir, baselen)) {
+		free(dir);
+		dir = NULL;
+	}
+	return dir;
+}
+
+
+/* Copy FILE to DST_FILE. */
+int
+copy_file(const char *file, const char *dst_file)
+{
+	int in_fd, out_fd;
+	struct stat st;
+	char *buf = NULL;
+	size_t bufsize;
+	size_t fsize;
+	int rc;
+	
+	in_fd = open(file, O_RDONLY);
+
+	if (in_fd == -1) {
+		error(0, errno,
+		       "cannot open source file %s for reading", file);
+		return 1;
+	}
+
+	if (fstat(in_fd, &st)) {
+		error(0, errno, "cannot stat source file %s", file);
+		close(in_fd);
+		return 1;
+	}
+
+	out_fd = creat(dst_file, CREAT_PERMISSIONS);
+	if (out_fd == -1) {
+		error(0, errno, "cannot create destination file %s", file);
+		close(in_fd);
+		return 1;
+	}
+
+	for (bufsize = fsize;
+	     bufsize > 0 && (buf = malloc(bufsize)) == NULL;
+	     bufsize /= 2);
+	if (bufsize == 0)
+		xalloc_die();
+
+	rc = 0;
+	fsize = st.st_size;
+	while (fsize > 0) {
+		size_t rest;
+		size_t rdbytes;
+
+		rest = fsize > bufsize ? bufsize : fsize;
+		rdbytes = read(in_fd, buf, rest);
+		if (rdbytes == -1) {
+			error(0, errno, "unexpected error reading %s", file);
+			rc = 1;
+			break;
+		}
+		rest = write(out_fd, buf, rdbytes);
+		if (rest == -1) {
+			error(0, errno, "unexpected error writing to %s",
+			       dst_file);
+			rc = 1;
+			break;
+		} else if (rest != rdbytes) {
+			error(0, 0, "short write on %s", dst_file);
+			rc = 1;
+		}
+		fsize -= rdbytes;
+	}
+	free(buf);
+
+	close(in_fd);
+	close(out_fd);
+	if (rc) {
+		unlink(dst_file);
+		return 1;
+	}
+	return 0;
+}
+
+/* Backup a file */
+int
+backup_file(const char *file)
+{
+	int rc = 0;
+	char *adir;
+	char *new_name;
+
+	if (backup_dir) {
+		if (file[0] == '/') 
+			new_name = concat_dir(backup_dir,
+					       last_component(file), NULL);
+		else
+			new_name = concat_dir(backup_dir, file, NULL);
+		if (access(new_name, F_OK) == 0) {
+			if (backup_type == no_backups) {
+				if (unlink(new_name)) 
+					error(0, errno,
+					      "cannot unlink backup file %s",
+					      new_name);
+				/* Try to continue anyway */
+			} else {
+				char *bfn = find_backup_file_name(new_name,
+								  backup_type);
+				copy_file(new_name, bfn);
+				/* Continue no matter what the result of
+				   copy_file was */
+			}
+		}
+	} else if (backup_type == no_backups)
+		return 0;
+	else 
+		new_name = find_backup_file_name(file, backup_type);
+	 
+	rc = copy_file(file, new_name);
+	free(new_name);
+	return rc;
+}
+
diff --git a/src/cmdline.opt b/src/cmdline.opt
index 2df4cfd..8037afb 100644
--- a/src/cmdline.opt
+++ b/src/cmdline.opt
@@ -53,7 +53,6 @@ BEGIN
        ed_list_add_assignment(optarg, p);
 END
        
-
 OPTION(id-version,V,VERSION,
        [<set ID3 version>])
 BEGIN
@@ -68,6 +67,18 @@ BEGIN
 	latin1_output = 1;
 END	
 
+OPTION(backup,,CONTROL,
+       [<backup before removal, choose version CONTROL>])
+BEGIN       
+       backup_type = xget_version ("--backup", optarg);
+END
+
+OPTION(backup-directory,,DIR,
+       [<backup to given DIR>])
+BEGIN
+       backup_dir = optarg;
+END       
+
 OPTIONS_END
 
 void
diff --git a/src/id3v2.c b/src/id3v2.c
index b8faa19..5ca9591 100644
--- a/src/id3v2.c
+++ b/src/id3v2.c
@@ -19,6 +19,14 @@
 void
 set_id3v2(const char *name)
 {
+	struct id3_file *file;
+	
+	file = id3_file_open(name, ID3_FILE_MODE_READWRITE);
+	if (!file)
+		error(1, errno, "cannot open file %s", name);
+	/*FIXME...*/
+	id3_file_close(file);
+	error(1, 0, "setting ID3 v2 frames is not yet implemented");
 }
 
 
diff --git a/src/idest.h b/src/idest.h
index 9dc16d8..50effa8 100644
--- a/src/idest.h
+++ b/src/idest.h
@@ -24,6 +24,7 @@
 #include <xalloc.h>
 #include <gl_linked_list.h>
 #include <argmatch.h>
+#include <backupfile.h>
 #include <id3tag.h>
 
 #define _(s) s
@@ -34,6 +35,8 @@
 #define DEFAULT_ED_LIST "title,album,comment,artist,year,genre"
 
 extern int latin1_output;
+extern enum backup_type backup_type;
+extern char *backup_dir;
 
 void set_id3v1(const char *name, const struct id3v1_block *);
 void query_id3v1(const char *name);
@@ -57,3 +60,6 @@ void ed_list_add_item(const char *id, gl_list_t list);
 void ed_list_print(void);
 void ed_list_add_assignment(const char *name, const char *value);
 
+
+/* backup.c */
+int backup_file(const char *file);
diff --git a/src/main.c b/src/main.c
index 2173147..9c34a93 100644
--- a/src/main.c
+++ b/src/main.c
@@ -18,13 +18,15 @@
 
 unsigned version_option = 2;
 int latin1_output = 0;
+enum backup_type backup_type;
+char *backup_dir;
 
 struct ed_item {
-	char *name;
-	char id[5];
+	char *name;                /* Printable name */
+	char id[5];                /* Item ID */
 	union {
-		gl_list_t vlist;
-		char *value;
+		gl_list_t vlist;   /* List of strings, used with --query */
+		char *value;       /* New value, used with --set */
 	} v;
 };
 
@@ -336,7 +338,7 @@ set_id3(const char *name)
 		
 		set_id3v1(name, &v1_block);
 	} else
-		error(1, 0, "setting ID3 v2 frames is not yet implemented");
+		set_id3v2(name);
 }
 
 void