src/util/os_file.h

   1 /*
   2  * Copyright 2019 Intel Corporation
   3  * SPDX-License-Identifier: MIT
   4  *
   5  * File operations helpers
   6  */
   7
   8 #ifndef _OS_FILE_H_
   9 #define _OS_FILE_H_
  10
  11 #include <stdbool.h>
  12 #include <stdio.h>
  13
  14 #ifdef  __cplusplus
  15 extern "C" {
  16 #endif
  17
  18 /*
  19  * Create a new file and opens it for writing-only.
  20  * If the given filename already exists, nothing is done and NULL is returned.
  21  * `errno` gets set to the failure reason; if that is not EEXIST, the caller
  22  * might want to do something other than trying again.
  23  */
  24 FILE *
  25 os_file_create_unique(const char *filename, int filemode);
  26
  27 /*
  28  * Duplicate a file descriptor, making sure not to keep it open after an exec*()
  29  */
  30 int
  31 os_dupfd_cloexec(int fd);
  32
  33 /*
  34  * Read a file.
  35  * Returns a char* that the caller must free(), or NULL and sets errno.
  36  * If size is not null and no error occured it's set to the size of the
  37  * file.
  38  */
  39 char *
  40 os_read_file(const char *filename, size_t *size);
  41
  42 /*
  43  * Try to determine if two file descriptors reference the same file description
  44  *
  45  * Return values:
  46  * - 0:   They reference the same file description
  47  * - > 0: They do not reference the same file description
  48  * - < 0: Unable to determine whether they reference the same file description
  49  */
  50 int
  51 os_same_file_description(int fd1, int fd2);
  52
  53 #ifdef __cplusplus
  54 }
  55 #endif
  56
  57 #endif /* _OS_FILE_H_ */