Edit
IABSD.fr/src/usr.bin/patch/backupfile.c
jcs
- usr.bin/patch/backupfile.c
-
/* $OpenBSD: backupfile.c,v 1.23 2024/03/22 19:22:23 jcs Exp $ */ /* * backupfile.c -- make Emacs style backup file names 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. */ /* * David MacKenzie <djm@ai.mit.edu>. Some algorithms adapted from GNU Emacs. */ #include <ctype.h> #include <dirent.h> #include <libgen.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include "backupfile.h" #define ISDIGIT(c) (isascii (c) && isdigit (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. */ 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((unsigned char)backup[base_length])) { for (p = &backup[base_length]; ISDIGIT((unsigned char)*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); }