23.10 Miscellaneous File Operations

Emacs has commands for performing many other operations on files. All operate on one file; they do not accept wildcard file names.

M-x view-file allows you to scan or read a file by sequential screenfuls. It reads a file name argument using the minibuffer. After reading the file into an Emacs buffer, view-file displays the beginning. You can then type <SPC> to scroll forward one windowful, or <DEL> to scroll backward. Various other commands are provided for moving around in the file, but none for changing it; type ? while viewing for a list of them. They are mostly the same as normal Emacs cursor motion commands. To exit from viewing, type q. The commands for viewing are defined by a special minor mode called View mode.

A related command, M-x view-buffer, views a buffer already present in Emacs. See Misc Buffer.

M-x insert-file (also C-x i) inserts a copy of the contents of the specified file into the current buffer at point, leaving point unchanged before the contents and the mark after them.

M-x write-region is the inverse of M-x insert-file; it copies the contents of the region into the specified file. M-x append-to-file adds the text of the region to the end of the specified file. See Accumulating Text. The variable write-region-inhibit-fsync applies to these commands, as well as saving files; see Customize Save.

M-x delete-file deletes the specified file, like the rm command in the shell. If you are deleting many files in one directory, it may be more convenient to use Dired (see Dired).

M-x rename-file reads two file names old and new using the minibuffer, then renames file old as new. If the file name new already exists, you must confirm with yes or renaming is not done; this is because renaming causes the old meaning of the name new to be lost. If old and new are on different file systems, the file old is copied and deleted.

If the argument new is just a directory name, the real new name is in that directory, with the same non-directory component as old. For example, M-x rename-file RET ~/foo RET /tmp RET renames ~/foo to /tmp/foo. The same rule applies to all the remaining commands in this section. All of them ask for confirmation when the new file name already exists, too.

The similar command M-x add-name-to-file is used to add an additional name to an existing file without removing its old name. The new name is created as a “hard link” to the existing file. The new name must belong on the same file system that the file is on. On MS-Windows, this command works only if the file resides in an NTFS file system. On MS-DOS, it works by copying the file.

M-x copy-file reads the file old and writes a new file named new with the same contents.

M-x make-symbolic-link reads two file names target and linkname, then creates a symbolic link named linkname, which points at target. The effect is that future attempts to open file linkname will refer to whatever file is named target at the time the opening is done, or will get an error if the name target is nonexistent at that time. This command does not expand the argument target, so that it allows you to specify a relative name as the target of the link.

Not all systems support symbolic links; on systems that don't support them, this command is not defined.