The file() command

This command provides all kinds of operations related to files: reading, transferring, locking, and archiving. It also provides modes to inspect the filesystem and operations on strings representing paths.

Full details can be found in the online documentation:

https://cmake.org/cmake/help/latest/command/file.html

The categories for available file() modes are reading, writing, filesystem, path conversion, transfer, locking, and archiving.

Reading

The following modes are available:

• file(READ <filename> <out> [OFFSET <o>] [LIMIT <max>] [HEX]) reads the file from <filename> to the <out> variable. The read optionally starts at offset <o> and follows the optional limit of <max> bytes. The HEX flag specifies that output should be converted to hexadecimal representation.
• file(STRINGS <filename> <out>) reads strings from the file at <filename> to the <out> variable...