Tcl_Access(3) Tcl Library Procedures Tcl_Access(3) ______________________________________________________________________________ NAME Tcl_Access, Tcl_Stat - check file(1,n) permissions and other attributes SYNOPSIS #include <tcl.h> int Tcl_Access(path, mode) int Tcl_Stat(path, statPtr) ARGUMENTS char *path (in(1,8)) Native name of the file(1,n) to check the attributes of. int mode (in(1,8)) 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(1,n) exists and has read(2,n,1 builtins), write(1,2) and execute permis- sions, respectively. F_OK just requests checking for the existence of the file. struct stat(1,2) *statPtr (out) The structure that contains the result. _________________________________________________________________ DESCRIPTION As of Tcl 8.4, the object-based APIs Tcl_FSAccess and Tcl_FSStat should be used in(1,8) preference to Tcl_Access and Tcl_Stat, wherever possible. There are two reasons for calling Tcl_Access and Tcl_Stat rather than calling system level functions access(2,5) and stat(1,2) directly. First, the Windows implementation of both functions fixes some bugs in(1,8) 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 possibility to reroute file(1,n) access(2,5) to alternative media or access(2,5) methods. Tcl_Access checks whether the process would be allowed to read(2,n,1 builtins), write(1,2) or test for existence of the file(1,n) (or other file(1,n) system object) whose name is pathname. If pathname is a symbolic link(1,2) on Unix, then per- missions of the file(1,n) referred by this symbolic link(1,2) are tested. On success (all requested permissions granted), zero is returned. On error(8,n) (at least one bit in(1,8) mode asked for a permission that is denied, or some other error(8,n) occurred), -1 is returned. Tcl_Stat fills the stat(1,2) structure statPtr with information about the specified file. You do not need any access(2,5) rights to the file(1,n) to get this information but you need search rights to all directories named(5,8) in(1,8) the path leading to the file. The stat(1,2) structure includes info(1,5,n) regard- ing device, inode (always 0 on Windows), privilege 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(2,5) time(1,2,n), last modification time(1,2,n), and creation time. If path exists, Tcl_Stat returns 0 and the stat(1,2) structure is filled with data. Otherwise, -1 is returned, and no stat(1,2) info(1,5,n) is given. KEYWORDS stat(1,2), access(2,5) Tcl 8.1 Tcl_Access(3)