src/basic/fileio.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <dirent.h>
   5 #include <fcntl.h>
   6 #include <stdbool.h>
   7 #include <stddef.h>
   8 #include <stdio.h>
   9 #include <sys/stat.h>
  10 #include <sys/types.h>
  11
  12 #include "macro.h"
  13 #include "time-util.h"
  14
  15 #define LONG_LINE_MAX (1U*1024U*1024U)
  16
  17 typedef enum {
  18         WRITE_STRING_FILE_CREATE                     = 1 << 0,
  19         WRITE_STRING_FILE_TRUNCATE                   = 1 << 1,
  20         WRITE_STRING_FILE_ATOMIC                     = 1 << 2,
  21         WRITE_STRING_FILE_AVOID_NEWLINE              = 1 << 3,
  22         WRITE_STRING_FILE_VERIFY_ON_FAILURE          = 1 << 4,
  23         WRITE_STRING_FILE_VERIFY_IGNORE_NEWLINE      = 1 << 5,
  24         WRITE_STRING_FILE_SYNC                       = 1 << 6,
  25         WRITE_STRING_FILE_DISABLE_BUFFER             = 1 << 7,
  26         WRITE_STRING_FILE_NOFOLLOW                   = 1 << 8,
  27         WRITE_STRING_FILE_MKDIR_0755                 = 1 << 9,
  28         WRITE_STRING_FILE_MODE_0600                  = 1 << 10,
  29         WRITE_STRING_FILE_SUPPRESS_REDUNDANT_VIRTUAL = 1 << 11,
  30
  31         /* And before you wonder, why write_string_file_atomic_label_ts() is a separate function instead of just one
  32            more flag here: it's about linking: we don't want to pull -lselinux into all users of write_string_file()
  33            and friends. */
  34
  35 } WriteStringFileFlags;
  36
  37 typedef enum {
  38         READ_FULL_FILE_SECURE              = 1 << 0, /* erase any buffers we employ internally, after use */
  39         READ_FULL_FILE_UNBASE64            = 1 << 1, /* base64 decode what we read */
  40         READ_FULL_FILE_UNHEX               = 1 << 2, /* hex decode what we read */
  41         READ_FULL_FILE_WARN_WORLD_READABLE = 1 << 3, /* if regular file, log at LOG_WARNING level if access mode above 0700 */
  42         READ_FULL_FILE_CONNECT_SOCKET      = 1 << 4, /* if socket inode, connect to it and read off it */
  43         READ_FULL_FILE_FAIL_WHEN_LARGER    = 1 << 5, /* fail loading if file is larger than specified size */
  44 } ReadFullFileFlags;
  45
  46 int fopen_unlocked(const char *path, const char *options, FILE **ret);
  47 int fdopen_unlocked(int fd, const char *options, FILE **ret);
  48 int take_fdopen_unlocked(int *fd, const char *options, FILE **ret);
  49 FILE* take_fdopen(int *fd, const char *options);
  50 DIR* take_fdopendir(int *dfd);
  51 FILE* open_memstream_unlocked(char **ptr, size_t *sizeloc);
  52 FILE* fmemopen_unlocked(void *buf, size_t size, const char *mode);
  53
  54 int write_string_stream_ts(FILE *f, const char *line, WriteStringFileFlags flags, const struct timespec *ts);
  55 static inline int write_string_stream(FILE *f, const char *line, WriteStringFileFlags flags) {
  56         return write_string_stream_ts(f, line, flags, NULL);
  57 }
  58 int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, const struct timespec *ts);
  59 static inline int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
  60         return write_string_file_ts(fn, line, flags, NULL);
  61 }
  62
  63 int write_string_filef(const char *fn, WriteStringFileFlags flags, const char *format, ...) _printf_(3, 4);
  64
  65 int read_one_line_file(const char *filename, char **line);
  66 int read_full_file_full(int dir_fd, const char *filename, uint64_t offset, size_t size, ReadFullFileFlags flags, const char *bind_name, char **ret_contents, size_t *ret_size);
  67 static inline int read_full_file(const char *filename, char **ret_contents, size_t *ret_size) {
  68         return read_full_file_full(AT_FDCWD, filename, UINT64_MAX, SIZE_MAX, 0, NULL, ret_contents, ret_size);
  69 }
  70
  71 int read_virtual_file_fd(int fd, size_t max_size, char **ret_contents, size_t *ret_size);
  72 int read_virtual_file(const char *filename, size_t max_size, char **ret_contents, size_t *ret_size);
  73 static inline int read_full_virtual_file(const char *filename, char **ret_contents, size_t *ret_size) {
  74         return read_virtual_file(filename, SIZE_MAX, ret_contents, ret_size);
  75 }
  76
  77 int read_full_stream_full(FILE *f, const char *filename, uint64_t offset, size_t size, ReadFullFileFlags flags, char **ret_contents, size_t *ret_size);
  78 static inline int read_full_stream(FILE *f, char **ret_contents, size_t *ret_size) {
  79         return read_full_stream_full(f, NULL, UINT64_MAX, SIZE_MAX, 0, ret_contents, ret_size);
  80 }
  81
  82 int verify_file(const char *fn, const char *blob, bool accept_extra_nl);
  83
  84 int executable_is_script(const char *path, char **interpreter);
  85
  86 int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field);
  87
  88 DIR *xopendirat(int dirfd, const char *name, int flags);
  89 int xfopenat(int dir_fd, const char *path, const char *mode, int flags, FILE **ret);
  90
  91 int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **ret, char **ret_path);
  92 int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **ret, char **ret_path);
  93
  94 int fflush_and_check(FILE *f);
  95 int fflush_sync_and_check(FILE *f);
  96
  97 int write_timestamp_file_atomic(const char *fn, usec_t n);
  98 int read_timestamp_file(const char *fn, usec_t *ret);
  99
 100 int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space);
 101
 102 typedef enum ReadLineFlags {
 103         READ_LINE_ONLY_NUL  = 1 << 0,
 104         READ_LINE_IS_A_TTY  = 1 << 1,
 105         READ_LINE_NOT_A_TTY = 1 << 2,
 106 } ReadLineFlags;
 107
 108 int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret);
 109
 110 static inline int read_line(FILE *f, size_t limit, char **ret) {
 111         return read_line_full(f, limit, 0, ret);
 112 }
 113
 114 static inline int read_nul_string(FILE *f, size_t limit, char **ret) {
 115         return read_line_full(f, limit, READ_LINE_ONLY_NUL, ret);
 116 }
 117
 118 int safe_fgetc(FILE *f, char *ret);
 119
 120 int warn_file_is_world_accessible(const char *filename, struct stat *st, const char *unit, unsigned line);
 121
 122 int fopen_mode_to_flags(const char *mode);