dirread, dirreadall - read directory #include <u.h>

#include <libc.h>

long dirread(int fd, Dir **buf)

long dirreadall(int fd, Dir **buf)

#define STATMAX 65535U

#define DIRMAX (sizeof(Dir)+STATMAX)

The data returned by a read (2) on a directory is a set of complete directory entries in a machine-independent format, exactly equivalent to the result of a stat (2) on each file or subdirectory in the directory. Dirread decodes the directory entries into a machine-dependent form. It reads from fd and unpacks the data into an array of Dir structures whose address is returned in *buf (see stat (2) for the layout of a Dir ). The array is allocated with malloc (2) each time dirread is called.

Dirreadall is like dirread , but reads in the entire directory; by contrast, dirread steps through a directory one read (2) at a time.

Directory entries have variable length. A successful read of a directory always returns an integral number of complete directory entries; dirread always returns complete Dir structures. See read (5) for more information.

The constant STATMAX is the maximum size that a directory entry can occupy. The constant DIRMAX is an upper limit on the size necessary to hold a Dir structure and all the associated data.

Dirread and dirreadall return the number of Dir structures filled in buf . The file offset is advanced by the number of bytes actually read.

/sys/src/libc/9sys/dirread.c intro (2), open (2), read (2) Dirread and Dirreadall return zero for end of file and a negative value for error. In either case, *buf is set to nil so the pointer can always be freed with impunity.

These functions set errstr .