cat command

Synopsis

With VFS (CONFIG_CMD_VFS):

cat <path>

Legacy (CONFIG_CMD_CAT):

cat <interface> <dev[:part]> <file>

Description

The cat command prints the contents of a file to standard output.

With VFS enabled, the file is read in chunks through the file uclass, so arbitrary file sizes are supported without loading the entire file into memory. The filesystem must be mounted first using mount.

path: absolute path in the VFS, e.g. /host/README

Example

VFS:

=> mount hostfs /host
=> cat /host/README
# SPDX-License-Identifier: GPL-2.0+
...

Legacy:

=> cat mmc 0:1 hello
hello world

Configuration

The VFS-based cat command is available when CONFIG_CMD_VFS=y. The legacy cat command is available when CONFIG_CMD_CAT=y.

Return value

The return value $? is set to 0 (true) if the file was successfully printed, 1 (false) otherwise.