Directory Access Functions - POSIX
The directory access functions provide an API for iterating through the entries within a directory. The fs_opendir() function initiates this procedure, and each subsequent call to fs_readdir_r() (until all entries have been examined) returns information about a particular entry in a struct fs_dirent. The fs_closedir() function releases any file system structures and locks.
Listing - Directory listing example code gives an example using the directory access functions to list the files in a directory.
void App_Fnct (void)
{
FS_DIR *p_dir;
struct fs_dirent dirent;
struct fs_dirent *p_dirent;
char str[50];
char *p_cwd_path;
fs_time_t ts;
.
.
.
p_dir = fs_opendir(p_cwd_path); /* Open dir. */
if (p_dir != (FS_DIR *)0) {
(void)fs_readdir_r(pdir, &dirent, &p_dirent); /* Rd first dir entry. */
if (p_dirent == (FS_DIRENT *)0) { /* If NULL ... dir is empty. */
APP_TRACE_INFO(("Empty dir: %s.\r\n", p_cwd_path));
} else { /* Fmt info for each entry. */
Str_Copy(str, "-r--r—r-- : ");
while (p_dirent != (struct dirent *)0) {
/* Chk if file is dir. */
if (DEF_BIT_IS_SET(dirent.Info.Attrib, FS_ENTRY_ATTRIB_DIR) == DEF_YES) {
str[0] = 'd';
}
/* Chk if file is rd only. */
if (DEF_BIT_IS_SET(dirent.Info.Attrib, FS_ENTRY_ATTRIB_WR) == DEF_YES) {
str[2] = 'w';
str[5] = 'w';
str[8] = 'w';
}
/* Get file size. */
if (p_dirent->Info.Size == 0) {
if (DEF_BIT_IS_CLR(dirent.Info.Attrib, FS_ENTRY_ATTRIB_DIR) == DEF_YES) {
Str_Copy(&str[11]," 0");
}
} else {
Str_FmtNbr_Int32U(dirent.Info.Size,
10, 10, '0', DEF_NO, DEF_NO, &str[11]);
}
/* Get file date/time. */
if (p_dirent->Info.DateTimeCreate.Month != 0) {
Str_Copy(&str[22],
(CPU_CHAR *)App_MonthNames[dirent.Info.DateTimeCreate.Month - 1]);
Str_FmtNbr_Int32U(dirent.Info.DateTimeWr.Day,
2, 10, ' ', DEF_NO, DEF_NO, &str[26]);
Str_FmtNbr_Int32U(dirent.Info.DateTimeWr.Hour,
2, 10, ' ', DEF_NO, DEF_NO, &str[29]);
Str_FmtNbr_Int32U(dirent.Info.DateTimeWr.Minute,
2, 10, ' ', DEF_NO, DEF_NO, &str[32]);
}
/* Output info for entry. */
APP_TRACE_INFO(("%s%s\r\n", str, dirent.Name));
/* Rd next dir entry. */
(void)fs_readdir_r(pdir, &dirent, &p_dirent);
}
}
fs_closedir(p_dir); /* Close dir. */
/* If dir could not be opened ... */
} else { /* ... dir does not exist. */
APP_TRACE_INFO(("Dir does not exist: %s.\r\n", p_cwd_path));
}
.
.
.
}
An example result of listing a directory is shown in the figure below.
The second argument fs_readdir_r(), is a pointer to a struct fs_dirent, which has two members. The first is Name, which holds the name of the entry; the second is Info, which has file information. For more information about the struct fs_dirent structure, see FS_DIR_ENTRY (struct fs_dirent).