From cfa37a7b1131abbab2e7d339b451f5f0e3198cc8 Mon Sep 17 00:00:00 2001 From: rsc Date: Sat, 10 Apr 2004 18:53:55 +0000 Subject: Lots of man pages. --- man/man3/dirread.3 | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 man/man3/dirread.3 (limited to 'man/man3/dirread.3') diff --git a/man/man3/dirread.3 b/man/man3/dirread.3 new file mode 100644 index 00000000..a7bd2ede --- /dev/null +++ b/man/man3/dirread.3 @@ -0,0 +1,103 @@ +.TH DIRREAD 3 +.SH NAME +dirread, dirreadall \- read directory +.SH SYNOPSIS +.B #include +.br +.B #include +.PP +.B +long dirread(int fd, Dir **buf) +.PP +.B +long dirreadall(int fd, Dir **buf) +.PP +.B +#define STATMAX 65535U +.PP +.B +#define DIRMAX (sizeof(Dir)+STATMAX) +.SH DESCRIPTION +The data returned by a +.IR read (2) +on a directory is a set of complete directory entries +in a machine-independent format, exactly equivalent to +the result of a +.IR stat (2) +on each file or subdirectory in the directory. +.I Dirread +decodes the directory entries into a machine-dependent form. +It reads from +.IR fd +and unpacks the data into an array of +.B Dir +structures +whose address is returned in +.B *buf +(see +.IR stat (2) +for the layout of a +.BR Dir ). +The array is allocated with +.IR malloc (2) +each time +.I dirread +is called. +.PP +.I Dirreadall +is like +.IR dirread , +but reads in the entire directory; by contrast, +.I dirread +steps through a directory one +.IR read (2) +at a time. +.PP +Directory entries have variable length. +A successful +.I read +of a directory always returns an integral number of complete directory entries; +.I dirread +always returns complete +.B Dir +structures. +See +.IR read (5) +for more information. +.PP +The constant +.B STATMAX +is the maximum size that a directory entry can occupy. +The constant +.B DIRMAX +is an upper limit on the size necessary to hold a +.B Dir +structure and all the associated data. +.PP +.I Dirread +and +.I dirreadall +return the number of +.B Dir +structures filled in +.BR buf . +The file offset is advanced by the number of bytes actually read. +.SH SOURCE +.B /sys/src/libc/9sys/dirread.c +.SH SEE ALSO +.IR intro (2), +.IR open (2), +.IR read (2) +.SH DIAGNOSTICS +.I Dirread +and +.I Dirreadall +return zero for end of file and a negative value for error. +In either case, +.B *buf +is set to +.B nil +so the pointer can always be freed with impunity. +.PP +These functions set +.IR errstr . -- cgit v1.2.3