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.TH DIRECTORY 3
.CT 2 dirs
.SH NAME
opendir, readdir, telldir, seekdir, closedir \(mi directory operations
.SH SYNOPSIS
.nf
.B #include <sys/types.h>
.B #include <ndir.h>
.PP
.B DIR *opendir(filename)
.B char *filename;
.PP
.B struct direct *readdir(dirp)
.B DIR *dirp;
.PP
.B long telldir(dirp)
.B DIR *dirp;
.PP
.B seekdir(dirp, loc)
.B DIR *dirp;
.B long loc;
.PP
.B closedir(dirp)
.B DIR *dirp;
.fi
.SH DESCRIPTION
.I Opendir
opens the directory named by
.I filename
and associates a `directory stream'
with it.
.I Opendir
returns a pointer to be used to identify the
directory stream
in subsequent operations.
The pointer value 0
is returned if
.I filename
cannot be accessed or is not a directory.
.PP
.I Readdir
returns a pointer to the next directory entry.
It returns 0
upon reaching the end of the directory or detecting
an invalid
.I seekdir
operation.
.PP
.I Telldir
returns the current location associated with the named
directory stream.
.PP
.I Seekdir
sets the position of the next
.I readdir
operation on the
directory stream.
The new position reverts to the one associated with the
directory stream
when the
.I telldir
operation was performed.
Values returned by
.I telldir
are good only for the lifetime of the
.B DIR
pointer from
which they are derived.
.PP
.I Closedir
causes the named
directory stream
to be closed,
and the structure associated with the
.B DIR
pointer to be freed.
.LP
.nf
.ftL
.ta \w'struct\ 'u +\w'direct\ 'u +\w'd_name[MAXNAMLEN+1];\ 'u
struct direct {
\fLu_long d_ino;\fR inode for the entry
\fLshort d_reclen;\fP don't use
\fLshort d_namlen;\fP equivalent to \fLstrlen(d_name)\fP
\fLchar d_name[MAXNAMLEN+1];\fP null-terminated entry name
\fL};\fR
.fi
.PP
The preferred way to search the current directory is:
.ft L
.nf
.ta 8n +8n +8n +8n
DIR *dirp;
dirp = opendir(".");
for(dp = readdir(dirp); dp != 0; dp = readdir(dir))
if(strcmp(dp->d_name, name) == 0)
break;
closedir(dirp);
/* found name if dp != 0 */
.fi
.ft P
.SH "SEE ALSO"
.IR dir (5),
.IR open (2),
.IR dirread (2),
.IR read (2),
.IR lseek (2),
.IR ftw (3)
.SH BUGS
The return values point to static data whose content is overwritten by each call.
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