diff options
Diffstat (limited to 'sysdeps/mach/hurd/getcwd.c')
| -rw-r--r-- | sysdeps/mach/hurd/getcwd.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/getcwd.c b/sysdeps/mach/hurd/getcwd.c new file mode 100644 index 0000000000..c0d9bcd567 --- /dev/null +++ b/sysdeps/mach/hurd/getcwd.c @@ -0,0 +1,250 @@ +/* Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <hurd.h> +#include <hurd/port.h> +#include <dirent.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <fcntl.h> + + +/* Get the pathname of the current working directory, and put it in SIZE + bytes of BUF. Returns NULL if the directory couldn't be determined or + SIZE was too small. If successful, returns BUF. In GNU, if BUF is + NULL, an array is allocated with `malloc'; the array is SIZE bytes long, + unless SIZE <= 0, in which case it is as big as necessary. */ + +char * +getcwd (char *buf, size_t size) +{ + error_t err; + dev_t rootdev, thisdev; + ino_t rootino, thisino; + char *file_name; + register char *file_namep; + struct stat st; + file_t parent; + char *dirbuf = NULL; + unsigned int dirbufsize = 0; + file_t crdir; + struct hurd_userlink crdir_ulink; + + inline void cleanup (void) + { + _hurd_port_free (&_hurd_ports[INIT_PORT_CRDIR], &crdir_ulink, crdir); + __mach_port_deallocate (__mach_task_self (), parent); + + if (dirbuf != NULL) + __vm_deallocate (__mach_task_self (), + (vm_address_t) dirbuf, dirbufsize); + } + + + if (size == 0) + { + if (buf != NULL) + { + errno = EINVAL; + return NULL; + } + + size = FILENAME_MAX * 4 + 1; /* Good starting guess. */ + } + + if (buf != NULL) + file_name = buf; + else + { + file_name = malloc (size); + if (file_name == NULL) + return NULL; + } + + file_namep = file_name + size; + *--file_namep = '\0'; + + /* Get a port to our root directory and stat it. */ + + crdir = _hurd_port_get (&_hurd_ports[INIT_PORT_CRDIR], &crdir_ulink); + if (err = __io_stat (crdir, &st)) + { + _hurd_port_free (&_hurd_ports[INIT_PORT_CRDIR], &crdir_ulink, crdir); + return __hurd_fail (err), NULL; + } + rootdev = st.st_dev; + rootino = st.st_ino; + + /* Get a port to our current working directory and stat it. */ + + if (err = __USEPORT (CWDIR, __mach_port_mod_refs (__mach_task_self (), + (parent = port), + MACH_PORT_RIGHT_SEND, + 1))) + { + _hurd_port_free (&_hurd_ports[INIT_PORT_CRDIR], &crdir_ulink, crdir); + return __hurd_fail (err), NULL; + } + if (err = __io_stat (parent, &st)) + { + cleanup (); + return __hurd_fail (err), NULL; + } + + thisdev = st.st_dev; + thisino = st.st_ino; + + while (!(thisdev == rootdev && thisino == rootino)) + { + /* PARENT is a port to the directory we are currently on; + THISDEV and THISINO are its device and node numbers. + Look in its parent (..) for a file with the same numbers. */ + + struct dirent *d; + dev_t dotdev; + ino_t dotino; + int mount_point; + file_t newp; + char *dirdata; + unsigned int dirdatasize; + int direntry, nentries; + + /* Look at the parent directory. */ + if (err = __hurd_file_name_lookup (crdir, parent, "..", O_READ, 0, &newp)) + goto lose; + __mach_port_deallocate (__mach_task_self (), parent); + parent = newp; + + /* Figure out if this directory is a mount point. */ + if (err = __io_stat (parent, &st)) + goto lose; + dotdev = st.st_dev; + dotino = st.st_ino; + mount_point = dotdev != thisdev; + + /* Search for the last directory. */ + direntry = 0; + dirdata = dirbuf; + dirdatasize = dirbufsize; + while (!(err = __dir_readdir (parent, &dirdata, &dirdatasize, + direntry, -1, 0, &nentries)) && + nentries != 0) + { + /* We have a block of directory entries. */ + + unsigned int offset; + + direntry += nentries; + + if (dirdata != dirbuf) + { + /* The data was passed out of line, so our old buffer is no + longer useful. Deallocate the old buffer and reset our + information for the new buffer. */ + __vm_deallocate (__mach_task_self (), + (vm_address_t) dirbuf, dirbufsize); + dirbuf = dirdata; + dirbufsize = round_page (dirdatasize); + } + + /* Iterate over the returned directory entries, looking for one + whose file number is THISINO. */ + + offset = 0; + while (offset < dirdatasize) + { + d = (struct dirent *) &dirdata[offset]; + offset += d->d_reclen; + + /* Ignore `.' and `..'. */ + if (d->d_name[0] == '.' && + (d->d_namlen == 1 || + (d->d_namlen == 2 && d->d_name[1] == '.'))) + continue; + + if (mount_point || d->d_ino == thisino) + { + file_t try; + if (err = __hurd_file_name_lookup (crdir, parent, d->d_name, + O_NOLINK, 0, &try)) + goto lose; + err = __io_stat (try, &st); + __mach_port_deallocate (__mach_task_self (), try); + if (err) + goto lose; + if (st.st_dev == thisdev && st.st_ino == thisino) + break; + } + } + } + + if (err) + goto lose; + else + { + /* Prepend the directory name just discovered. */ + + if (file_namep - file_name < d->d_namlen + 1) + { + if (buf != NULL) + { + errno = ERANGE; + return NULL; + } + else + { + size *= 2; + buf = realloc (file_name, size); + if (buf == NULL) + { + free (file_name); + return NULL; + } + file_namep = &buf[file_namep - file_name]; + file_name = buf; + } + } + file_namep -= d->d_namlen; + (void) memcpy (file_namep, d->d_name, d->d_namlen); + *--file_namep = '/'; + } + + /* The next iteration will find the name of the directory we + just searched through. */ + thisdev = dotdev; + thisino = dotino; + } + + if (file_namep == &file_name[size - 1]) + /* We found nothing and got all the way to the root. + So the root is our current directory. */ + *--file_namep = '/'; + + memmove (file_name, file_namep, file_name + size - file_namep); + cleanup (); + return file_name; + + lose: + cleanup (); + return NULL; +} |