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director(3) [minix man page]

DIRECTORY(3)						     Library Functions Manual						      DIRECTORY(3)

NAME
directory, opendir, readdir, rewinddir, closedir, telldir, seekdir - directory routines SYNOPSIS
#include <sys/types.h> #include <dirent.h> DIR *opendir(const char *dirname) struct dirent *readdir(DIR *dirp) void rewinddir(DIR *dirp) int closedir(DIR *dirp) #define _MINIX 1 #include <sys/types.h> #include <dirent.h> long telldir(DIR *dirp) int seekdir(DIR *dirp, long pos) DESCRIPTION
These routines form a system independent interface to access directories. Opendir() opens the directory dirname and returns a pointer to this open directory stream. Readdir() reads one entry from the directory as a pointer to a structure containing the field d_name, a character array containing the null-terminated name of the entry. Rewinddir() allows the directory to be read again from the beginning. Closedir() closes the directory and releases administrative data. The Minix specific functions telldir() and seekdir() allow one to get the current position in the directory file and to return there later. Seekdir() may only be called with a position returned by telldir() or 0 (rewind). These functions should not be used in portable programs. SEE ALSO
dir(5). DIAGNOSTICS
Opendir() returns a null pointer if dirname can't be opened, or if it can't allocate enough memory for the DIR structure. Readdir() returns null if there are no more directory entries or on error. Closedir() and seekdir() returns 0 on success, -1 on error. Telldir() returns -1 on error. All of them set errno appropriately. Readdir() will only set errno on error, not on end-of-dir, so you should set errno to zero before- hand, and check its value if readdir() returns null. NOTES
The return value of readdir() needs to be copied before the next operation on the same directory if it is to be saved. AUTHOR
Kees J. Bot (kjb@cs.vu.nl) DIRECTORY(3)

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DIRECTORY(3)						     Library Functions Manual						      DIRECTORY(3)

NAME
opendir, readdir, telldir, seekdir, rewinddir, closedir - directory operations SYNOPSIS
#include <sys/types.h> #include <sys/dir.h> DIR *opendir(filename) char *filename; struct direct *readdir(dirp) DIR *dirp; long telldir(dirp) DIR *dirp; seekdir(dirp, loc) DIR *dirp; long loc; rewinddir(dirp) DIR *dirp; closedir(dirp) DIR *dirp; DESCRIPTION
Opendir opens the directory named by filename and associates a directory stream with it. Opendir returns a pointer to be used to identify the directory stream in subsequent operations. The pointer NULL is returned if filename cannot be accessed, or if it cannot malloc(3) enough memory to hold the whole thing. Readdir returns a pointer to the next directory entry. It returns NULL upon reaching the end of the directory or detecting an invalid seekdir operation. Telldir returns the current location associated with the named directory stream. Seekdir sets the position of the next readdir operation on the directory stream. The new position reverts to the one associated with the directory stream when the telldir operation was performed. Values returned by telldir are good only for the lifetime of the DIR pointer from which they are derived. If the directory is closed and then reopened, the telldir value may be invalidated due to undetected direc- tory compaction. It is safe to use a previous telldir value immediately after a call to opendir and before any calls to readdir. Rewinddir resets the position of the named directory stream to the beginning of the directory. Closedir closes the named directory stream and frees the structure associated with the DIR pointer. Sample code which searchs a directory for entry ``name'' is: len = strlen(name); dirp = opendir("."); for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) if (dp->d_namlen == len && !strcmp(dp->d_name, name)) { closedir(dirp); return FOUND; } closedir(dirp); return NOT_FOUND; SEE ALSO
open(2), close(2), read(2), lseek(2), dir(5) 4.2 Berkeley Distribution September 24, 1985 DIRECTORY(3)
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