diff options
author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2017-09-24 14:27:21 +0200 |
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committer | Sven Eden <yamakuzure@gmx.net> | 2017-11-22 08:22:23 +0100 |
commit | 68bb1246bf0dc56f61b6d655694ddd4df647167c (patch) | |
tree | d3ec4ecc37c903334f496981f12ead2973836c2f /src/basic/fileio.c | |
parent | e0e02387f7dfc8ab4f415212264666476fc4a21f (diff) |
fileio: return 0 from read_one_line_file on success
Fixup for f4b51a2d09. Suggested by Evgeny Vereshchagin.
Diffstat (limited to 'src/basic/fileio.c')
-rw-r--r-- | src/basic/fileio.c | 160 |
1 files changed, 105 insertions, 55 deletions
diff --git a/src/basic/fileio.c b/src/basic/fileio.c index 333effa5f..3990d4dce 100644 --- a/src/basic/fileio.c +++ b/src/basic/fileio.c @@ -30,6 +30,7 @@ #include "alloc-util.h" #include "ctype.h" +#include "def.h" #include "env-util.h" #include "escape.h" #include "fd-util.h" @@ -52,17 +53,13 @@ #define READ_FULL_BYTES_MAX (4U*1024U*1024U) -int write_string_stream_ts( - FILE *f, - const char *line, - WriteStringFileFlags flags, - struct timespec *ts) { +int write_string_stream_ts(FILE *f, const char *line, bool enforce_newline, struct timespec *ts) { assert(f); assert(line); fputs(line, f); - if (!(flags & WRITE_STRING_FILE_AVOID_NEWLINE) && !endswith(line, "\n")) + if (enforce_newline && !endswith(line, "\n")) fputc('\n', f); if (ts) { @@ -72,18 +69,10 @@ int write_string_stream_ts( return -errno; } - if (flags & WRITE_STRING_FILE_SYNC) - return fflush_sync_and_check(f); - else - return fflush_and_check(f); + return fflush_and_check(f); } -static int write_string_file_atomic( - const char *fn, - const char *line, - WriteStringFileFlags flags, - struct timespec *ts) { - +static int write_string_file_atomic(const char *fn, const char *line, bool enforce_newline, bool do_fsync) { _cleanup_fclose_ FILE *f = NULL; _cleanup_free_ char *p = NULL; int r; @@ -97,28 +86,22 @@ static int write_string_file_atomic( (void) fchmod_umask(fileno(f), 0644); - r = write_string_stream_ts(f, line, flags, ts); - if (r < 0) - goto fail; + r = write_string_stream(f, line, enforce_newline); + if (r >= 0 && do_fsync) + r = fflush_sync_and_check(f); - if (rename(p, fn) < 0) { - r = -errno; - goto fail; + if (r >= 0) { + if (rename(p, fn) < 0) + r = -errno; } - return 0; + if (r < 0) + (void) unlink(p); -fail: - (void) unlink(p); return r; } -int write_string_file_ts( - const char *fn, - const char *line, - WriteStringFileFlags flags, - struct timespec *ts) { - +int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, struct timespec *ts) { _cleanup_fclose_ FILE *f = NULL; int q, r; @@ -131,7 +114,8 @@ int write_string_file_ts( if (flags & WRITE_STRING_FILE_ATOMIC) { assert(flags & WRITE_STRING_FILE_CREATE); - r = write_string_file_atomic(fn, line, flags, ts); + r = write_string_file_atomic(fn, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE), + flags & WRITE_STRING_FILE_SYNC); if (r < 0) goto fail; @@ -164,10 +148,16 @@ int write_string_file_ts( } } - r = write_string_stream_ts(f, line, flags, ts); + r = write_string_stream_ts(f, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE), ts); if (r < 0) goto fail; + if (flags & WRITE_STRING_FILE_SYNC) { + r = fflush_sync_and_check(f); + if (r < 0) + return r; + } + return 0; fail: @@ -188,7 +178,7 @@ fail: int read_one_line_file(const char *fn, char **line) { _cleanup_fclose_ FILE *f = NULL; - char t[LINE_MAX], *c; + int r; assert(fn); assert(line); @@ -197,21 +187,8 @@ int read_one_line_file(const char *fn, char **line) { if (!f) return -errno; - if (!fgets(t, sizeof(t), f)) { - - if (ferror(f)) - return errno > 0 ? -errno : -EIO; - - t[0] = 0; - } - - c = strdup(t); - if (!c) - return -ENOMEM; - truncate_nl(c); - - *line = c; - return 0; + r = read_line(f, LONG_LINE_MAX, line); + return r < 0 ? r : 0; } int verify_file(const char *fn, const char *blob, bool accept_extra_nl) { @@ -270,11 +247,11 @@ int read_full_stream(FILE *f, char **contents, size_t *size) { if (st.st_size > READ_FULL_BYTES_MAX) return -E2BIG; - /* Start with the right file size, but be prepared for files from /proc which generally report a file - * size of 0. Note that we increase the size to read here by one, so that the first read attempt - * already makes us notice the EOF. */ + /* Start with the right file size, but be prepared for + * files from /proc which generally report a file size + * of 0 */ if (st.st_size > 0) - n = st.st_size + 1; + n = st.st_size; } l = 0; @@ -287,13 +264,12 @@ int read_full_stream(FILE *f, char **contents, size_t *size) { return -ENOMEM; buf = t; - errno = 0; k = fread(buf + l, 1, n - l, f); if (k > 0) l += k; if (ferror(f)) - return errno > 0 ? -errno : -EIO; + return -errno; if (feof(f)) break; @@ -1550,3 +1526,77 @@ int mkdtemp_malloc(const char *template, char **ret) { return 0; } #endif // 0 + +static inline void funlockfilep(FILE **f) { + funlockfile(*f); +} + +int read_line(FILE *f, size_t limit, char **ret) { + _cleanup_free_ char *buffer = NULL; + size_t n = 0, allocated = 0, count = 0; + + assert(f); + + /* Something like a bounded version of getline(). + * + * Considers EOF, \n and \0 end of line delimiters, and does not include these delimiters in the string + * returned. + * + * Returns the number of bytes read from the files (i.e. including delimiters — this hence usually differs from + * the number of characters in the returned string). When EOF is hit, 0 is returned. + * + * The input parameter limit is the maximum numbers of characters in the returned string, i.e. excluding + * delimiters. If the limit is hit we fail and return -ENOBUFS. + * + * If a line shall be skipped ret may be initialized as NULL. */ + + if (ret) { + if (!GREEDY_REALLOC(buffer, allocated, 1)) + return -ENOMEM; + } + + { + _cleanup_(funlockfilep) FILE *flocked = f; + flockfile(f); + + for (;;) { + int c; + + if (n >= limit) + return -ENOBUFS; + + errno = 0; + c = fgetc_unlocked(f); + if (c == EOF) { + /* if we read an error, and have no data to return, then propagate the error */ + if (ferror_unlocked(f) && n == 0) + return errno > 0 ? -errno : -EIO; + + break; + } + + count++; + + if (IN_SET(c, '\n', 0)) /* Reached a delimiter */ + break; + + if (ret) { + if (!GREEDY_REALLOC(buffer, allocated, n + 2)) + return -ENOMEM; + + buffer[n] = (char) c; + } + + n++; + } + } + + if (ret) { + buffer[n] = 0; + + *ret = buffer; + buffer = NULL; + } + + return (int) count; +} |