diff options
Diffstat (limited to 'src/lib/fs')
| -rw-r--r-- | src/lib/fs/files.c | 20 | ||||
| -rw-r--r-- | src/lib/fs/files.h | 2 |
2 files changed, 22 insertions, 0 deletions
diff --git a/src/lib/fs/files.c b/src/lib/fs/files.c index b4a432701f..aff78db718 100644 --- a/src/lib/fs/files.c +++ b/src/lib/fs/files.c @@ -734,6 +734,26 @@ read_file_to_str, (const char *filename, int flags, struct stat *stat_out)) return string; } +/** Attempt to read a file <b>fname</b>. If the file's contents is + * equal to the string <b>str</b>, return 0. Otherwise, attempt to + * overwrite the file with the contents of <b>str</b> and return + * the value of write_str_to_file(). + */ +int +write_str_to_file_if_not_equal(const char *fname, const char *str) +{ + char *fstr = read_file_to_str(fname, RFTS_IGNORE_MISSING, NULL); + int rv; + + if (!fstr || strcmp(str, fstr)) { + rv = write_str_to_file(fname, str, 0); + } else { + rv = 0; + } + tor_free(fstr); + return rv; +} + #if !defined(HAVE_GETDELIM) || defined(TOR_UNIT_TESTS) #include "ext/getdelim.c" #endif diff --git a/src/lib/fs/files.h b/src/lib/fs/files.h index 6eeba85e89..f0178e2b5b 100644 --- a/src/lib/fs/files.h +++ b/src/lib/fs/files.h @@ -93,6 +93,8 @@ int append_bytes_to_file(const char *fname, const char *str, size_t len, int write_bytes_to_new_file(const char *fname, const char *str, size_t len, int bin); +int write_str_to_file_if_not_equal(const char *fname, const char *str); + /** Flag for read_file_to_str: open the file in binary mode. */ #define RFTS_BIN 1 /** Flag for read_file_to_str: it's okay if the file doesn't exist. */ |