archie/tcl7.3/compat/opendir.c
2024-05-27 16:13:40 +02:00

107 lines
1.9 KiB
C

/*
* opendir.c --
*
* This file provides dirent-style directory-reading procedures
* for V7 Unix systems that don't have such procedures. The
* origin of this code is unclear, but it seems to have come
* originally from Larry Wall.
*
*/
#include "tclInt.h"
#include "tclUnix.h"
#undef DIRSIZ
#define DIRSIZ(dp) \
((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
/*
* open a directory.
*/
DIR *
opendir(name)
char *name;
{
register DIR *dirp;
register int fd;
char *myname;
myname = ((*name == '\0') ? "." : name);
if ((fd = open(myname, 0, 0)) == -1)
return NULL;
if ((dirp = (DIR *)ckalloc(sizeof(DIR))) == NULL) {
close (fd);
return NULL;
}
dirp->dd_fd = fd;
dirp->dd_loc = 0;
return dirp;
}
/*
* read an old style directory entry and present it as a new one
*/
#ifndef pyr
#define ODIRSIZ 14
struct olddirect {
ino_t od_ino;
char od_name[ODIRSIZ];
};
#else /* a Pyramid in the ATT universe */
#define ODIRSIZ 248
struct olddirect {
long od_ino;
short od_fill1, od_fill2;
char od_name[ODIRSIZ];
};
#endif
/*
* get next entry in a directory.
*/
struct dirent *
readdir(dirp)
register DIR *dirp;
{
register struct olddirect *dp;
static struct dirent dir;
for (;;) {
if (dirp->dd_loc == 0) {
dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf,
DIRBLKSIZ);
if (dirp->dd_size <= 0)
return NULL;
}
if (dirp->dd_loc >= dirp->dd_size) {
dirp->dd_loc = 0;
continue;
}
dp = (struct olddirect *)(dirp->dd_buf + dirp->dd_loc);
dirp->dd_loc += sizeof(struct olddirect);
if (dp->od_ino == 0)
continue;
dir.d_ino = dp->od_ino;
strncpy(dir.d_name, dp->od_name, ODIRSIZ);
dir.d_name[ODIRSIZ] = '\0'; /* insure null termination */
dir.d_namlen = strlen(dir.d_name);
dir.d_reclen = DIRSIZ(&dir);
return (&dir);
}
}
/*
* close a directory.
*/
void
closedir(dirp)
register DIR *dirp;
{
close(dirp->dd_fd);
dirp->dd_fd = -1;
dirp->dd_loc = 0;
ckfree((char *) dirp);
}