Tcl_Access(3) Tcl Library Procedures Tcl_Access(3)______________________________________________________________________________NAME
Tcl_Access, Tcl_Stat - check file permissions and other attributes
char *path (in) Native name of the file to check the
int mode (in) Mask consisting of one or more of R_OK,
W_OK, X_OK and F_OK. R_OK, W_OK and X_OK
request checking whether the file exists
and has read, write and execute permis‐
sions, respectively. F_OK just requests
checking for the existence of the file.
stat *statPtr (out) The structure that contains the result.
There are two reasons for calling Tcl_Access and Tcl_Stat rather than
calling system level functions access and stat directly. First, the
Windows implementation of both functions fixes some bugs in the system
level calls. Second, both Tcl_Access and Tcl_Stat (as well as
Tcl_OpenFileChannelProc) hook into a linked list of functions. This
allows the possibity to reroute file access to alternative media or
Tcl_Access checks whether the process would be allowed to read, write
or test for existence of the file (or other file system object) whose
name is pathname. If pathname is a symbolic link on Unix, then per‐
missions of the file referred by this symbolic link are tested.
On success (all requested permissions granted), zero is returned. On
error (at least one bit in mode asked for a permission that is denied,
or some other error occurred), -1 is returned.
Tcl_Stat fills the stat structure statPtr with information about the
specified file. You do not need any access rights to the file to get
this information but you need search rights to all directories named in
the path leading to the file. The stat structure includes info regard‐
ing device, inode (always 0 on Windows), priviledge mode, nlink (always
1 on Windows), user id (always 0 on Windows), group id (always 0 on
Windows), rdev (same as device on Windows), size, last access time,
last modification time, and creation time.
If path exists, Tcl_Stat returns 0 and the stat structure is filled
with data. Otherwise, -1 is returned, and no stat info is given.
Tcl 8.1 Tcl_Access(3)