New File Manipulation Commands and Options

The new file channels command returns a list of open I/O channels, which can be sockets, regular files, or channels created by extensions. It accepts an optional glob pattern argument (e.g., sock*) to constrain the list.

The file atime and file mtime commands now accept an optional argument to set the access time or modification time of the specified file. This gives you the ability to perform the equivalent of the Unix touch command in pure Tcl code.

In addition to the previous ability to set file permissions using the same octal code format as the Unix chmod command, the -permissions option of the file attributes command now allows you to set file permissions symbolically. You can use the same symbolic attributes as the Unix chmod command (for example, u+s,go-rw to add sticky bit for user and remove read and write permissions for group and other). A simplified ls-style string, of the form rwxrwxrwx (the string must be 9 characters) is also supported (for example, rwxr-xr-t is equivalent to 01755).