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getdirentries(2) [opendarwin man page]

GETDIRENTRIES(2)					      BSD System Calls Manual						  GETDIRENTRIES(2)

NAME
getdirentries -- get directory entries in a filesystem independent format SYNOPSIS
#include <sys/types.h> #include <sys/dirent.h> int getdirentries(int fd, char *buf, int nbytes, long *basep); DESCRIPTION
Getdirentries() reads directory entries from the directory referenced by the file descriptor fd into the buffer pointed to by buf, in a filesystem independent format. Up to nbytes of data will be transferred. Nbytes must be greater than or equal to the block size associated with the file, see stat(2). Some filesystems may not support getdirentries() with buffers smaller than this size. The data in the buffer is a series of dirent structures each containing the following entries: u_int32_t d_fileno; /* file number of entry */ u_int16_t d_reclen; /* length of this record */ u_int8_t d_type; /* file type, see below */ u_int8_t d_namlen; /* length of string in d_name */ char d_name[MAXNAMELEN + 1]; /* see below */ The d_fileno entry is a number which is unique for each distinct file in the filesystem. Files that are linked by hard links (see link(2)) have the same d_fileno. Users of getdirentries() should skip entries with d_fileno = 0, as such entries represent files which have been deleted but not yet removed from the directory entry. The d_reclen entry is the length, in bytes, of the directory record. The d_name entry contains a null terminated file name. The d_namlen entry specifies the length of the file name excluding the null byte. Thus the actual size of d_name may vary from 1 to MAXNAMELEN + 1. d_type is a integer representing the type of the directory entry. The following types are defined in <sys/dirent.h>: #define DT_UNKNOWN 0 #define DT_FIFO 1 #define DT_CHR 2 #define DT_DIR 4 #define DT_BLK 6 #define DT_REG 8 #define DT_LNK 10 #define DT_SOCK 12 #define DT_WHT 14 Entries may be separated by extra space. The d_reclen entry may be used as an offset from the start of a dirent structure to the next struc- ture, if any. The actual number of bytes transferred is returned. The current position pointer associated with fd is set to point to the next block of entries. The pointer may not advance by the number of bytes returned by getdirentries(). A value of zero is returned when the end of the directory has been reached. Getdirentries() writes the position of the block read into the location pointed to by basep. Alternatively, the current position pointer may be set and retrieved by lseek(2). The current position pointer should only be set to a value returned by lseek(2), a value returned in the location pointed to by basep, or zero. RETURN VALUES
If successful, the number of bytes actually transferred is returned. Otherwise, -1 is returned and the global variable errno is set to indi- cate the error. ERRORS
Getdirentries() will fail if: [EBADF] fd is not a valid file descriptor open for reading. [EFAULT] Either buf or basep point outside the allocated address space. [EIO] An I/O error occurred while reading from or writing to the file system. SEE ALSO
open(2), lseek(2) HISTORY
The getdirentries() function first appeared in 4.4BSD. BSD
June 9, 1993 BSD

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getdirentries(2)						System Calls Manual						  getdirentries(2)

NAME
getdirentries - Gets directory entries in a file-system independent format. SYNOPSIS
#include <dirent.h> int getdirentries( int fd, char *buf, int nbytes, long *basep ); PARAMETERS
Specifies the file descriptor of a directory to be read. Points to a buffer containing the directory entries as dirent structures. Speci- fies the maximum amount of data to be transferred, in bytes. Points to the position of the block read. DESCRIPTION
The getdirentries() function reads directory entries from a directory into a buffer. The entries are returned as dirent structures, a file-system independent format. This call is not the POSIX-defined way to process directory entries. For POSIX interfaces, use the opendir(3),readdir(3), and closedir(3) library calls for reading and interpreting directory entries. The nbytes parameter should be greater than or equal to the block size associated with the file. (See stat(2).) Some file systems do not support the getdirentries() function with buffers smaller than this size. The entries returned by the getdirentries() function into the location pointed to by buf can be separated by extra space. The getdirentries() function writes the position of the block read into the location pointed to by the basep parameter. Alternatively, the current position pointer can be set and retrieved by lseek(). The current position pointer should only be set to a value returned by lseek(), a value returned in the location pointed to by basep, or 0 (zero). Upon successful completion, the actual number of bytes transferred is returned and the current position pointer associated with the fd parameter is set to point to the next block of entries. The file descriptor pointer might not advance by the same number of bytes returned by the getdirentries() function. A value of 0 (zero) is returned when the end of the directory has been reached. RETURN VALUES
Upon successful completion, the actual number of bytes transferred is returned. Otherwise, -1 is returned and errno is set to indicate the error. ERRORS
If the getdirentries() function fails, errno is set to one of the following values: The fd parameter is not a valid file descriptor open for reading. Either the buf or basep parameter points outside the allocated address space. Either the fd parameter is not a valid file descriptor for a directory or the buffer is too small. An I/O error occurred while the operating system was reading from or writing to the file system. RELATED INFORMATION
Functions: open(2), lseek(2) delim off getdirentries(2)
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