72 lines
1.5 KiB
C
72 lines
1.5 KiB
C
/*
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opendir -- open a directory stream
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last edit: 16-Jun-1987 D A Gwyn
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*/
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#include <errno.h>
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#include <stdlib.h>
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#include <sys/errno.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <dirent.h>
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#ifdef BSD_SYSV
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#define open _open /* avoid emulation overhead */
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#endif
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typedef void *pointer; /* (void *) if you have it */
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extern int open(const char *path, int flags, int mode);
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extern int close(int d);
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extern int fstat(int fd, struct stat *buf);
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#ifndef NULL
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#define NULL 0
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#endif
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#ifndef O_RDONLY
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#define O_RDONLY 0
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#endif
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#ifndef S_ISDIR /* macro to test for directory file */
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#define S_ISDIR( mode ) (((mode) & S_IFMT) == S_IFDIR)
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#endif
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DIR *
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opendir(const char *dirname) /* name of directory */
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{
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register DIR *dirp; /* -> malloc'ed storage */
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register int fd; /* file descriptor for read */
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struct stat sbuf; /* result of fstat() */
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if ( (fd = open( dirname, O_RDONLY, 0 )) < 0 )
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return NULL; /* errno set by open() */
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if ( fstat( fd, &sbuf ) != 0 || !S_ISDIR( sbuf.st_mode ) )
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{
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(void)close( fd );
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errno = ENOTDIR;
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return NULL; /* not a directory */
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}
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if ( (dirp = (DIR *)malloc( sizeof(DIR) )) == NULL
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|| (dirp->dd_buf = (char *)malloc( (unsigned)DIRBUF )) == NULL
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) {
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register int serrno = errno;
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/* errno set to ENOMEM by sbrk() */
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if ( dirp != NULL )
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free( (pointer)dirp );
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(void)close( fd );
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errno = serrno;
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return NULL; /* not enough memory */
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}
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dirp->dd_fd = fd;
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dirp->dd_loc = dirp->dd_size = 0; /* refill needed */
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return dirp;
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}
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