1757e8328SLionel Sambuc /*
2757e8328SLionel Sambuc * $OpenBSD: backupfile.c,v 1.19 2006/03/11 19:41:30 otto Exp $
3757e8328SLionel Sambuc * $DragonFly: src/usr.bin/patch/backupfile.c,v 1.5 2008/08/11 00:05:06 joerg Exp $
4*0a6a1f1dSLionel Sambuc * $NetBSD: backupfile.c,v 1.15 2014/04/11 17:30:03 christos Exp $
5757e8328SLionel Sambuc */
6757e8328SLionel Sambuc
7757e8328SLionel Sambuc /*
8757e8328SLionel Sambuc * backupfile.c -- make Emacs style backup file names
9757e8328SLionel Sambuc *
10757e8328SLionel Sambuc * Copyright (C) 1990 Free Software Foundation, Inc.
11757e8328SLionel Sambuc *
12757e8328SLionel Sambuc * This program is free software; you can redistribute it and/or modify it
13757e8328SLionel Sambuc * without restriction.
14757e8328SLionel Sambuc *
15757e8328SLionel Sambuc * This program is distributed in the hope that it will be useful, but WITHOUT
16757e8328SLionel Sambuc * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17757e8328SLionel Sambuc * FITNESS FOR A PARTICULAR PURPOSE.
18757e8328SLionel Sambuc */
19757e8328SLionel Sambuc
20757e8328SLionel Sambuc /*
21757e8328SLionel Sambuc * David MacKenzie <djm@ai.mit.edu>. Some algorithms adapted from GNU Emacs.
22757e8328SLionel Sambuc */
23757e8328SLionel Sambuc
24757e8328SLionel Sambuc #include <sys/cdefs.h>
25*0a6a1f1dSLionel Sambuc __RCSID("$NetBSD: backupfile.c,v 1.15 2014/04/11 17:30:03 christos Exp $");
26757e8328SLionel Sambuc
27757e8328SLionel Sambuc #include <ctype.h>
28757e8328SLionel Sambuc #include <dirent.h>
29757e8328SLionel Sambuc #include <libgen.h>
30757e8328SLionel Sambuc #include <stdio.h>
31757e8328SLionel Sambuc #include <stdlib.h>
32757e8328SLionel Sambuc #include <string.h>
33757e8328SLionel Sambuc #include <unistd.h>
34757e8328SLionel Sambuc
35757e8328SLionel Sambuc #include "backupfile.h"
36757e8328SLionel Sambuc
37757e8328SLionel Sambuc
38757e8328SLionel Sambuc #define ISDIGIT(c) (isascii ((unsigned char)c) && isdigit ((unsigned char)c))
39757e8328SLionel Sambuc
40757e8328SLionel Sambuc /* Which type of backup file names are generated. */
41757e8328SLionel Sambuc enum backup_type backup_type = none;
42757e8328SLionel Sambuc
43757e8328SLionel Sambuc /*
44757e8328SLionel Sambuc * The extension added to file names to produce a simple (as opposed to
45757e8328SLionel Sambuc * numbered) backup file name.
46757e8328SLionel Sambuc */
47757e8328SLionel Sambuc const char *simple_backup_suffix = "~";
48757e8328SLionel Sambuc
49757e8328SLionel Sambuc static char *concat(const char *, const char *);
50757e8328SLionel Sambuc static char *make_version_name(const char *, int);
51757e8328SLionel Sambuc static int max_backup_version(const char *, const char *);
52757e8328SLionel Sambuc static int version_number(const char *, const char *, size_t);
53757e8328SLionel Sambuc static int argmatch(const char *, const char **);
54757e8328SLionel Sambuc static void invalid_arg(const char *, const char *, int);
55757e8328SLionel Sambuc
56757e8328SLionel Sambuc /*
57757e8328SLionel Sambuc * Return the name of the new backup file for file FILE, allocated with
58757e8328SLionel Sambuc * malloc. Return 0 if out of memory. FILE must not end with a '/' unless it
59757e8328SLionel Sambuc * is the root directory. Do not call this function if backup_type == none.
60757e8328SLionel Sambuc */
61757e8328SLionel Sambuc char *
find_backup_file_name(const char * file)62757e8328SLionel Sambuc find_backup_file_name(const char *file)
63757e8328SLionel Sambuc {
64757e8328SLionel Sambuc char *dir, *base_versions, *tmp_file;
65757e8328SLionel Sambuc int highest_backup;
66757e8328SLionel Sambuc
67757e8328SLionel Sambuc if (backup_type == simple)
68757e8328SLionel Sambuc return concat(file, simple_backup_suffix);
69757e8328SLionel Sambuc tmp_file = strdup(file);
70757e8328SLionel Sambuc if (tmp_file == NULL)
71757e8328SLionel Sambuc return NULL;
72757e8328SLionel Sambuc base_versions = concat(basename(tmp_file), ".~");
73757e8328SLionel Sambuc free(tmp_file);
74757e8328SLionel Sambuc if (base_versions == NULL)
75757e8328SLionel Sambuc return NULL;
76757e8328SLionel Sambuc tmp_file = strdup(file);
77757e8328SLionel Sambuc if (tmp_file == NULL) {
78757e8328SLionel Sambuc free(base_versions);
79757e8328SLionel Sambuc return NULL;
80757e8328SLionel Sambuc }
81757e8328SLionel Sambuc dir = dirname(tmp_file);
82757e8328SLionel Sambuc if (dir == NULL) {
83757e8328SLionel Sambuc free(base_versions);
84757e8328SLionel Sambuc free(tmp_file);
85757e8328SLionel Sambuc return NULL;
86757e8328SLionel Sambuc }
87757e8328SLionel Sambuc highest_backup = max_backup_version(base_versions, dir);
88757e8328SLionel Sambuc free(base_versions);
89757e8328SLionel Sambuc free(tmp_file);
90757e8328SLionel Sambuc if (backup_type == numbered_existing && highest_backup == 0)
91757e8328SLionel Sambuc return concat(file, simple_backup_suffix);
92757e8328SLionel Sambuc return make_version_name(file, highest_backup + 1);
93757e8328SLionel Sambuc }
94757e8328SLionel Sambuc
95757e8328SLionel Sambuc /*
96757e8328SLionel Sambuc * Return the number of the highest-numbered backup file for file FILE in
97757e8328SLionel Sambuc * directory DIR. If there are no numbered backups of FILE in DIR, or an
98757e8328SLionel Sambuc * error occurs reading DIR, return 0. FILE should already have ".~" appended
99757e8328SLionel Sambuc * to it.
100757e8328SLionel Sambuc */
101757e8328SLionel Sambuc static int
max_backup_version(const char * file,const char * dir)102757e8328SLionel Sambuc max_backup_version(const char *file, const char *dir)
103757e8328SLionel Sambuc {
104757e8328SLionel Sambuc DIR *dirp;
105757e8328SLionel Sambuc struct dirent *dp;
106757e8328SLionel Sambuc int highest_version, this_version;
107757e8328SLionel Sambuc size_t file_name_length;
108757e8328SLionel Sambuc
109757e8328SLionel Sambuc dirp = opendir(dir);
110757e8328SLionel Sambuc if (dirp == NULL)
111757e8328SLionel Sambuc return 0;
112757e8328SLionel Sambuc
113757e8328SLionel Sambuc highest_version = 0;
114757e8328SLionel Sambuc file_name_length = strlen(file);
115757e8328SLionel Sambuc
116757e8328SLionel Sambuc while ((dp = readdir(dirp)) != NULL) {
117757e8328SLionel Sambuc if (dp->d_namlen <= file_name_length)
118757e8328SLionel Sambuc continue;
119757e8328SLionel Sambuc
120757e8328SLionel Sambuc this_version = version_number(file, dp->d_name, file_name_length);
121757e8328SLionel Sambuc if (this_version > highest_version)
122757e8328SLionel Sambuc highest_version = this_version;
123757e8328SLionel Sambuc }
124757e8328SLionel Sambuc closedir(dirp);
125757e8328SLionel Sambuc return highest_version;
126757e8328SLionel Sambuc }
127757e8328SLionel Sambuc
128757e8328SLionel Sambuc /*
129757e8328SLionel Sambuc * Return a string, allocated with malloc, containing "FILE.~VERSION~".
130757e8328SLionel Sambuc * Return 0 if out of memory.
131757e8328SLionel Sambuc */
132757e8328SLionel Sambuc static char *
make_version_name(const char * file,int version)133757e8328SLionel Sambuc make_version_name(const char *file, int version)
134757e8328SLionel Sambuc {
135757e8328SLionel Sambuc char *backup_name;
136757e8328SLionel Sambuc
137757e8328SLionel Sambuc if (asprintf(&backup_name, "%s.~%d~", file, version) == -1)
138757e8328SLionel Sambuc return NULL;
139757e8328SLionel Sambuc return backup_name;
140757e8328SLionel Sambuc }
141757e8328SLionel Sambuc
142757e8328SLionel Sambuc /*
143757e8328SLionel Sambuc * If BACKUP is a numbered backup of BASE, return its version number;
144757e8328SLionel Sambuc * otherwise return 0. BASE_LENGTH is the length of BASE. BASE should
145757e8328SLionel Sambuc * already have ".~" appended to it.
146757e8328SLionel Sambuc */
147757e8328SLionel Sambuc static int
version_number(const char * base,const char * backup,size_t base_length)148757e8328SLionel Sambuc version_number(const char *base, const char *backup, size_t base_length)
149757e8328SLionel Sambuc {
150757e8328SLionel Sambuc int version;
151757e8328SLionel Sambuc const char *p;
152757e8328SLionel Sambuc
153757e8328SLionel Sambuc version = 0;
154757e8328SLionel Sambuc if (!strncmp(base, backup, base_length) && ISDIGIT(backup[base_length])) {
155757e8328SLionel Sambuc for (p = &backup[base_length]; ISDIGIT(*p); ++p)
156757e8328SLionel Sambuc version = version * 10 + *p - '0';
157757e8328SLionel Sambuc if (p[0] != '~' || p[1])
158757e8328SLionel Sambuc version = 0;
159757e8328SLionel Sambuc }
160757e8328SLionel Sambuc return version;
161757e8328SLionel Sambuc }
162757e8328SLionel Sambuc
163757e8328SLionel Sambuc /*
164757e8328SLionel Sambuc * Return the newly-allocated concatenation of STR1 and STR2. If out of
165757e8328SLionel Sambuc * memory, return 0.
166757e8328SLionel Sambuc */
167757e8328SLionel Sambuc static char *
concat(const char * str1,const char * str2)168757e8328SLionel Sambuc concat(const char *str1, const char *str2)
169757e8328SLionel Sambuc {
170757e8328SLionel Sambuc char *newstr;
171757e8328SLionel Sambuc
172757e8328SLionel Sambuc if (asprintf(&newstr, "%s%s", str1, str2) == -1)
173757e8328SLionel Sambuc return NULL;
174757e8328SLionel Sambuc return newstr;
175757e8328SLionel Sambuc }
176757e8328SLionel Sambuc
177757e8328SLionel Sambuc /*
178757e8328SLionel Sambuc * If ARG is an unambiguous match for an element of the null-terminated array
179757e8328SLionel Sambuc * OPTLIST, return the index in OPTLIST of the matched element, else -1 if it
180757e8328SLionel Sambuc * does not match any element or -2 if it is ambiguous (is a prefix of more
181757e8328SLionel Sambuc * than one element).
182757e8328SLionel Sambuc */
183757e8328SLionel Sambuc static int
argmatch(const char * arg,const char ** optlist)184757e8328SLionel Sambuc argmatch(const char *arg, const char **optlist)
185757e8328SLionel Sambuc {
186757e8328SLionel Sambuc int i; /* Temporary index in OPTLIST. */
187757e8328SLionel Sambuc size_t arglen; /* Length of ARG. */
188757e8328SLionel Sambuc int matchind = -1; /* Index of first nonexact match. */
189757e8328SLionel Sambuc int ambiguous = 0; /* If nonzero, multiple nonexact match(es). */
190757e8328SLionel Sambuc
191757e8328SLionel Sambuc arglen = strlen(arg);
192757e8328SLionel Sambuc
193757e8328SLionel Sambuc /* Test all elements for either exact match or abbreviated matches. */
194757e8328SLionel Sambuc for (i = 0; optlist[i]; i++) {
195757e8328SLionel Sambuc if (!strncmp(optlist[i], arg, arglen)) {
196757e8328SLionel Sambuc if (strlen(optlist[i]) == arglen)
197757e8328SLionel Sambuc /* Exact match found. */
198757e8328SLionel Sambuc return i;
199757e8328SLionel Sambuc else if (matchind == -1)
200757e8328SLionel Sambuc /* First nonexact match found. */
201757e8328SLionel Sambuc matchind = i;
202757e8328SLionel Sambuc else
203757e8328SLionel Sambuc /* Second nonexact match found. */
204757e8328SLionel Sambuc ambiguous = 1;
205757e8328SLionel Sambuc }
206757e8328SLionel Sambuc }
207757e8328SLionel Sambuc if (ambiguous)
208757e8328SLionel Sambuc return -2;
209757e8328SLionel Sambuc else
210757e8328SLionel Sambuc return matchind;
211757e8328SLionel Sambuc }
212757e8328SLionel Sambuc
213757e8328SLionel Sambuc /*
214757e8328SLionel Sambuc * Error reporting for argmatch. KIND is a description of the type of entity
215757e8328SLionel Sambuc * that was being matched. VALUE is the invalid value that was given. PROBLEM
216757e8328SLionel Sambuc * is the return value from argmatch.
217757e8328SLionel Sambuc */
218757e8328SLionel Sambuc static void
invalid_arg(const char * kind,const char * value,int problem)219757e8328SLionel Sambuc invalid_arg(const char *kind, const char *value, int problem)
220757e8328SLionel Sambuc {
221757e8328SLionel Sambuc fprintf(stderr, "patch: ");
222757e8328SLionel Sambuc if (problem == -1)
223757e8328SLionel Sambuc fprintf(stderr, "invalid");
224757e8328SLionel Sambuc else /* Assume -2. */
225757e8328SLionel Sambuc fprintf(stderr, "ambiguous");
226757e8328SLionel Sambuc fprintf(stderr, " %s `%s'\n", kind, value);
227757e8328SLionel Sambuc }
228757e8328SLionel Sambuc
229757e8328SLionel Sambuc static const char *backup_args[] = {
230*0a6a1f1dSLionel Sambuc "none", "never", "simple", "nil", "existing", "t", "numbered", 0
231757e8328SLionel Sambuc };
232757e8328SLionel Sambuc
233757e8328SLionel Sambuc static enum backup_type backup_types[] = {
234*0a6a1f1dSLionel Sambuc none, simple, simple, numbered_existing,
235757e8328SLionel Sambuc numbered_existing, numbered, numbered
236757e8328SLionel Sambuc };
237757e8328SLionel Sambuc
238757e8328SLionel Sambuc /*
239757e8328SLionel Sambuc * Return the type of backup indicated by VERSION. Unique abbreviations are
240757e8328SLionel Sambuc * accepted.
241757e8328SLionel Sambuc */
242757e8328SLionel Sambuc enum backup_type
get_version(const char * version)243757e8328SLionel Sambuc get_version(const char *version)
244757e8328SLionel Sambuc {
245757e8328SLionel Sambuc int i;
246757e8328SLionel Sambuc
247757e8328SLionel Sambuc if (version == NULL || *version == '\0')
248757e8328SLionel Sambuc return numbered_existing;
249757e8328SLionel Sambuc i = argmatch(version, backup_args);
250757e8328SLionel Sambuc if (i >= 0)
251757e8328SLionel Sambuc return backup_types[i];
252757e8328SLionel Sambuc invalid_arg("version control type", version, i);
253757e8328SLionel Sambuc exit(2);
254757e8328SLionel Sambuc }
255