File System / Process / CLI / Shell

Load at compile-time

• #load .

  • Returns a []u8  of the file contents at compile time.

  • The loaded data is baked into your program.

  • You can provide a type name as a second argument; interpreting the data as being of that type.

• #load_directory .

  • Loads all files within a directory, at compile time.

    • The data is name: string  and data: []byte .

  • All the data of those files will be baked into your program.

• #load_hash .

  • Returns a constant integer of the hash of a file’s contents at compile time.

  • Available hashes: "adler32" , "crc32" , "crc64" , "fnv32" , "fnv64" , "fnv32a" , "fnv64a" , "murmur32" , or "murmur64" .

core:os2

• core:os/os2

• It will replace core:os  in 2026.

• (2025-07-07)

  • It's not on the web docs yet. Technically it's still WIP, though some parts of it are quite usable.

• process_exec

  • run with piped output and wait.

Process Execute

• Must :

  • This procedure expects that stdout  and stderr  fields of the desc  parameter are left at default, i.e. a nil  value. You can not capture stdout/stderr and redirect it to a file at the same time.

  • assert(desc.stdout == nil, "Cannot redirect stdout when it's being captured", loc)

  • assert(desc.stderr == nil, "Cannot redirect stderr when it's being captured", loc)

• Memory :

  • This procedure does not free stdout  and stderr  slices before an error is returned. Make sure to call delete  on these slices.

Process Start

• process_start

• Asynchronous and more configurable, but requires more setup.

• See   Shells .

  • Further investigations .

core:os

• Handle .

  • Used to perform many operations.

• File_Info .

• open .

• read .

  • read_entire_file_from_filename .

    • core/os/os.odin:131 : Automatically does open  and then close .

  • read_entire_file_from_handle .

    • core/os/os.odin:141 : Does not do open  or close .

• write .

• flush .

• close .

• exists .

• if_file .

• make_directory .

• remove .

• rename .

core:c/libc

• core:c/libc

• Not native in Odin.

• Has system  for just running basic command-line commands

• (2025-10-29)

• I was using libc.system  for some basic commands, but once I learned how to use the os2 , I think is much better and should be the go to for CLI.