/* * Copyright © 2015 Collabora, Ltd. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial * portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include <stdio.h> #include <errno.h> #include <time.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdlib.h> #include "file-util.h" static int current_time_str(char *str, size_t len, const char *fmt) { time_t t; struct tm *t_local; int ret; t = time(NULL); t_local = localtime(&t); if (!t_local) { errno = ETIME; return -1; } ret = strftime(str, len, fmt, t_local); if (ret == 0) { errno = ETIME; return -1; } return ret; } static int create_file_excl(const char *fname) { return open(fname, O_RDWR | O_CLOEXEC | O_CREAT | O_EXCL, 00666); } /** Create a unique file with date and time in the name * * \param path File path * \param prefix File name prefix. * \param suffix File name suffix. * \param[out] name_out Buffer for the resulting file name. * \param name_len Number of bytes usable in name_out. * \return stdio FILE pointer, or NULL on failure. * * Create and open a new file with the name concatenated from * path/prefix, date and time, and suffix. If a file with this name * already exists, an counter number is added to the end of the * date and time sub-string. The counter is increased until a free file * name is found. * * Once creating the file succeeds, the name of the file is in name_out. * On failure, the contents of name_out are undefined and errno is set. */ FILE * file_create_dated(const char *path, const char *prefix, const char *suffix, char *name_out, size_t name_len) { char timestr[128]; int ret; int fd; int cnt = 0; int with_path; with_path = path && path[0]; if (current_time_str(timestr, sizeof(timestr), "%F_%H-%M-%S") < 0) return NULL; ret = snprintf(name_out, name_len, "%s%s%s%s%s", with_path ? path : "", with_path ? "/" : "", prefix, timestr, suffix); if (ret < 0 || (size_t)ret >= name_len) { errno = ENOBUFS; return NULL; } fd = create_file_excl(name_out); while (fd == -1 && errno == EEXIST) { cnt++; ret = snprintf(name_out, name_len, "%s%s%s%s-%d%s", with_path ? path : "", with_path ? "/" : "", prefix, timestr, cnt, suffix); if (ret < 0 || (size_t)ret >= name_len) { errno = ENOBUFS; return NULL; } fd = create_file_excl(name_out); } if (fd == -1) return NULL; return fdopen(fd, "w"); }