From 899b50b126e7d87f1e4f1da51d7ad725393c9103 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Thu, 12 Feb 2015 12:52:21 +0200 Subject: [PATCH] shared: add file_create_dated() helper For easy creation of unique new files. I'm looking at you, screenshooter. This code is based on timeline.c weston_timeline_do_open(). Signed-off-by: Pekka Paalanen Tested-by: Nobuhiko Tanibata Reviewed-by: Daniel Stone --- Makefile.am | 2 + shared/file-util.c | 118 +++++++++++++++++++++++++++++++++++++++++++++ shared/file-util.h | 40 +++++++++++++++ 3 files changed, 160 insertions(+) create mode 100644 shared/file-util.c create mode 100644 shared/file-util.h diff --git a/Makefile.am b/Makefile.am index 7fb9e17a..4e219e14 100644 --- a/Makefile.am +++ b/Makefile.am @@ -884,6 +884,8 @@ libshared_la_SOURCES = \ shared/config-parser.c \ shared/option-parser.c \ shared/config-parser.h \ + shared/file-util.c \ + shared/file-util.h \ shared/os-compatibility.c \ shared/os-compatibility.h diff --git a/shared/file-util.c b/shared/file-util.c new file mode 100644 index 00000000..cd4f17d7 --- /dev/null +++ b/shared/file-util.c @@ -0,0 +1,118 @@ +/* + * Copyright © 2015 Collabora, Ltd. + * + * Permission to use, copy, modify, distribute, and sell this software and + * its documentation for any purpose is hereby granted without fee, provided + * that the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation, and that the name of the copyright holders not be used in + * advertising or publicity pertaining to distribution of the software + * without specific, written prior permission. The copyright holders make + * no representations about the suitability of this software for any + * purpose. It is provided "as is" without express or implied warranty. + * + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS + * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY + * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER + * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF + * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "config.h" + +#include +#include +#include +#include +#include +#include + +#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_prefix Path and file name prefix. + * \param suffix File name suffix. + * \param name_out[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_prefix, const char *suffix, + char *name_out, size_t name_len) +{ + char timestr[128]; + int ret; + int fd; + int cnt = 0; + + if (current_time_str(timestr, sizeof(timestr), "%F_%H-%M-%S") < 0) + return NULL; + + ret = snprintf(name_out, name_len, "%s%s%s", + 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-%d%s", + 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"); +} diff --git a/shared/file-util.h b/shared/file-util.h new file mode 100644 index 00000000..847c948b --- /dev/null +++ b/shared/file-util.h @@ -0,0 +1,40 @@ +/* + * Copyright © 2015 Collabora, Ltd. + * + * Permission to use, copy, modify, distribute, and sell this software and + * its documentation for any purpose is hereby granted without fee, provided + * that the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation, and that the name of the copyright holders not be used in + * advertising or publicity pertaining to distribution of the software + * without specific, written prior permission. The copyright holders make + * no representations about the suitability of this software for any + * purpose. It is provided "as is" without express or implied warranty. + * + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS + * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY + * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER + * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF + * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef WESTON_FILE_UTIL_H +#define WESTON_FILE_UTIL_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include + +FILE * +file_create_dated(const char *path_prefix, const char *suffix, + char *name_out, size_t name_len); + +#ifdef __cplusplus +} +#endif + +#endif /* WESTON_FILE_UTIL_H */