246 lines
6.2 KiB
C
246 lines
6.2 KiB
C
/*-
|
|
* Copyright (C) 1990 Free Software Foundation, Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* without restriction.
|
|
*
|
|
* 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.
|
|
*
|
|
* backupfile.c -- make Emacs style backup file names
|
|
*
|
|
* David MacKenzie <djm@ai.mit.edu>. Some algorithms adapted from GNU Emacs.
|
|
*
|
|
* $OpenBSD: backupfile.c,v 1.20 2009/10/27 23:59:41 deraadt Exp $
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include <ctype.h>
|
|
#include <dirent.h>
|
|
#include <libgen.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include "backupfile.h"
|
|
|
|
|
|
#define ISDIGIT(c) (isascii ((unsigned char)c) && isdigit ((unsigned char)c))
|
|
|
|
/* Which type of backup file names are generated. */
|
|
enum backup_type backup_type = none;
|
|
|
|
/*
|
|
* The extension added to file names to produce a simple (as opposed to
|
|
* numbered) backup file name.
|
|
*/
|
|
const char *simple_backup_suffix = "~";
|
|
|
|
static char *concat(const char *, const char *);
|
|
static char *make_version_name(const char *, int);
|
|
static int max_backup_version(const char *, const char *);
|
|
static int version_number(const char *, const char *, size_t);
|
|
static int argmatch(const char *, const char **);
|
|
static void invalid_arg(const char *, const char *, int);
|
|
|
|
/*
|
|
* Return the name of the new backup file for file FILE, allocated with
|
|
* malloc. Return 0 if out of memory. FILE must not end with a '/' unless it
|
|
* is the root directory. Do not call this function if backup_type == none.
|
|
*/
|
|
char *
|
|
find_backup_file_name(const char *file)
|
|
{
|
|
char *dir, *base_versions, *tmp_file;
|
|
int highest_backup;
|
|
|
|
if (backup_type == simple)
|
|
return concat(file, simple_backup_suffix);
|
|
tmp_file = strdup(file);
|
|
if (tmp_file == NULL)
|
|
return NULL;
|
|
base_versions = concat(basename(tmp_file), ".~");
|
|
free(tmp_file);
|
|
if (base_versions == NULL)
|
|
return NULL;
|
|
tmp_file = strdup(file);
|
|
if (tmp_file == NULL) {
|
|
free(base_versions);
|
|
return NULL;
|
|
}
|
|
dir = dirname(tmp_file);
|
|
if (dir == NULL) {
|
|
free(base_versions);
|
|
free(tmp_file);
|
|
return NULL;
|
|
}
|
|
highest_backup = max_backup_version(base_versions, dir);
|
|
free(base_versions);
|
|
free(tmp_file);
|
|
if (backup_type == numbered_existing && highest_backup == 0)
|
|
return concat(file, simple_backup_suffix);
|
|
return make_version_name(file, highest_backup + 1);
|
|
}
|
|
|
|
/*
|
|
* Return the number of the highest-numbered backup file for file FILE in
|
|
* directory DIR. If there are no numbered backups of FILE in DIR, or an
|
|
* error occurs reading DIR, return 0. FILE should already have ".~" appended
|
|
* to it.
|
|
*/
|
|
static int
|
|
max_backup_version(const char *file, const char *dir)
|
|
{
|
|
DIR *dirp;
|
|
struct dirent *dp;
|
|
int highest_version, this_version;
|
|
size_t file_name_length;
|
|
|
|
dirp = opendir(dir);
|
|
if (dirp == NULL)
|
|
return 0;
|
|
|
|
highest_version = 0;
|
|
file_name_length = strlen(file);
|
|
|
|
while ((dp = readdir(dirp)) != NULL) {
|
|
if (dp->d_namlen <= file_name_length)
|
|
continue;
|
|
|
|
this_version = version_number(file, dp->d_name, file_name_length);
|
|
if (this_version > highest_version)
|
|
highest_version = this_version;
|
|
}
|
|
closedir(dirp);
|
|
return highest_version;
|
|
}
|
|
|
|
/*
|
|
* Return a string, allocated with malloc, containing "FILE.~VERSION~".
|
|
* Return 0 if out of memory.
|
|
*/
|
|
static char *
|
|
make_version_name(const char *file, int version)
|
|
{
|
|
char *backup_name;
|
|
|
|
if (asprintf(&backup_name, "%s.~%d~", file, version) == -1)
|
|
return NULL;
|
|
return backup_name;
|
|
}
|
|
|
|
/*
|
|
* If BACKUP is a numbered backup of BASE, return its version number;
|
|
* otherwise return 0. BASE_LENGTH is the length of BASE. BASE should
|
|
* already have ".~" appended to it.
|
|
*/
|
|
static int
|
|
version_number(const char *base, const char *backup, size_t base_length)
|
|
{
|
|
int version;
|
|
const char *p;
|
|
|
|
version = 0;
|
|
if (!strncmp(base, backup, base_length) && ISDIGIT(backup[base_length])) {
|
|
for (p = &backup[base_length]; ISDIGIT(*p); ++p)
|
|
version = version * 10 + *p - '0';
|
|
if (p[0] != '~' || p[1])
|
|
version = 0;
|
|
}
|
|
return version;
|
|
}
|
|
|
|
/*
|
|
* Return the newly-allocated concatenation of STR1 and STR2. If out of
|
|
* memory, return 0.
|
|
*/
|
|
static char *
|
|
concat(const char *str1, const char *str2)
|
|
{
|
|
char *newstr;
|
|
|
|
if (asprintf(&newstr, "%s%s", str1, str2) == -1)
|
|
return NULL;
|
|
return newstr;
|
|
}
|
|
|
|
/*
|
|
* If ARG is an unambiguous match for an element of the null-terminated array
|
|
* OPTLIST, return the index in OPTLIST of the matched element, else -1 if it
|
|
* does not match any element or -2 if it is ambiguous (is a prefix of more
|
|
* than one element).
|
|
*/
|
|
static int
|
|
argmatch(const char *arg, const char **optlist)
|
|
{
|
|
int i; /* Temporary index in OPTLIST. */
|
|
size_t arglen; /* Length of ARG. */
|
|
int matchind = -1; /* Index of first nonexact match. */
|
|
int ambiguous = 0; /* If nonzero, multiple nonexact match(es). */
|
|
|
|
arglen = strlen(arg);
|
|
|
|
/* Test all elements for either exact match or abbreviated matches. */
|
|
for (i = 0; optlist[i]; i++) {
|
|
if (!strncmp(optlist[i], arg, arglen)) {
|
|
if (strlen(optlist[i]) == arglen)
|
|
/* Exact match found. */
|
|
return i;
|
|
else if (matchind == -1)
|
|
/* First nonexact match found. */
|
|
matchind = i;
|
|
else
|
|
/* Second nonexact match found. */
|
|
ambiguous = 1;
|
|
}
|
|
}
|
|
if (ambiguous)
|
|
return -2;
|
|
else
|
|
return matchind;
|
|
}
|
|
|
|
/*
|
|
* Error reporting for argmatch. KIND is a description of the type of entity
|
|
* that was being matched. VALUE is the invalid value that was given. PROBLEM
|
|
* is the return value from argmatch.
|
|
*/
|
|
static void
|
|
invalid_arg(const char *kind, const char *value, int problem)
|
|
{
|
|
fprintf(stderr, "patch: ");
|
|
if (problem == -1)
|
|
fprintf(stderr, "invalid");
|
|
else /* Assume -2. */
|
|
fprintf(stderr, "ambiguous");
|
|
fprintf(stderr, " %s `%s'\n", kind, value);
|
|
}
|
|
|
|
static const char *backup_args[] = {
|
|
"none", "never", "simple", "nil", "existing", "t", "numbered", 0
|
|
};
|
|
|
|
static enum backup_type backup_types[] = {
|
|
none, simple, simple, numbered_existing,
|
|
numbered_existing, numbered, numbered
|
|
};
|
|
|
|
/*
|
|
* Return the type of backup indicated by VERSION. Unique abbreviations are
|
|
* accepted.
|
|
*/
|
|
enum backup_type
|
|
get_version(const char *version)
|
|
{
|
|
int i;
|
|
|
|
if (version == NULL || *version == '\0')
|
|
return numbered_existing;
|
|
i = argmatch(version, backup_args);
|
|
if (i >= 0)
|
|
return backup_types[i];
|
|
invalid_arg("version control type", version, i);
|
|
exit(2);
|
|
}
|