[PATCH v4] cmd: cat: add new command

Heinrich Schuchardt xypron.glpk at gmx.de
Sun Aug 21 09:35:08 CEST 2022


On 8/19/22 10:35, Roger Knecht wrote:
> Add cat command to print file content to standard out
>
> Signed-off-by: Roger Knecht <rknecht at pm.me>
> ---
> v4:
>   - Return only values from enum command_ret_t in do_cat()
>   - Use calloc() instead of malloc() for zero initialized memory
>   - Make use of CONFIG_SYS_LONGHELP
>   - Improved error messages
>
> v3:
>   - Disable 'cat' by default (CONFIG_CMD_CAT=n)
>   - Enable 'cat' in sandbox and sandbox64 defconfig
>   - Use map_to_sysmem() to fix "phys_to_virt: Cannot map sandbox address"
>   - Use puts() instead of a loop
>   - Added python test
>   - Addd usage documentation
>
> v2:
>   - Moved cat from boot to shell commands
>   - Added MAINTAINERS entry
>   - Added comments
>   - Improved variable naming
>
>   MAINTAINERS                        |  5 ++
>   cmd/Kconfig                        |  6 ++
>   cmd/Makefile                       |  1 +
>   cmd/cat.c                          | 88 ++++++++++++++++++++++++++++++
>   configs/sandbox64_defconfig        |  1 +
>   configs/sandbox_defconfig          |  1 +
>   doc/usage/cmd/cat.rst              | 49 +++++++++++++++++
>   test/py/tests/test_cat/conftest.py | 33 +++++++++++
>   test/py/tests/test_cat/test_cat.py | 22 ++++++++
>   9 files changed, 206 insertions(+)
>   create mode 100644 cmd/cat.c
>   create mode 100644 doc/usage/cmd/cat.rst
>   create mode 100644 test/py/tests/test_cat/conftest.py
>   create mode 100644 test/py/tests/test_cat/test_cat.py
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5857fbf398..2864f84274 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -765,6 +765,11 @@ M:	Simon Glass <sjg at chromium.org>
>   S:	Maintained
>   F:	tools/buildman/
>
> +CAT
> +M:	Roger Knecht <rknecht at pm.me>
> +S:	Maintained
> +F:	cmd/cat.c
> +
>   CFI FLASH
>   M:	Stefan Roese <sr at denx.de>
>   S:	Maintained
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 211ebe9c87..ce7e876475 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -1531,6 +1531,12 @@ endmenu
>
>   menu "Shell scripting commands"
>
> +config CMD_CAT
> +	bool "cat"
> +	default n
> +	help
> +	  Print file to standard output
> +
>   config CMD_ECHO
>   	bool "echo"
>   	default y
> diff --git a/cmd/Makefile b/cmd/Makefile
> index 6e87522b62..1d2590e958 100644
> --- a/cmd/Makefile
> +++ b/cmd/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_CMD_BOOTZ) += bootz.o
>   obj-$(CONFIG_CMD_BOOTI) += booti.o
>   obj-$(CONFIG_CMD_BTRFS) += btrfs.o
>   obj-$(CONFIG_CMD_BUTTON) += button.o
> +obj-$(CONFIG_CMD_CAT) += cat.o
>   obj-$(CONFIG_CMD_CACHE) += cache.o
>   obj-$(CONFIG_CMD_CBFS) += cbfs.o
>   obj-$(CONFIG_CMD_CLK) += clk.o
> diff --git a/cmd/cat.c b/cmd/cat.c
> new file mode 100644
> index 0000000000..c2c17b7abc
> --- /dev/null
> +++ b/cmd/cat.c
> @@ -0,0 +1,88 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2022
> + * Roger Knecht <rknecht at pm.de>
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +#include <fs.h>
> +#include <malloc.h>
> +#include <mapmem.h>
> +
> +static int do_cat(struct cmd_tbl *cmdtp, int flag, int argc,
> +		  char *const argv[])
> +{
> +	char *ifname;
> +	char *dev;
> +	char *file;
> +	char *buffer;
> +	phys_addr_t buffer_sysmem_addr;
> +	loff_t file_size;
> +
> +	if (argc < 4)
> +		return CMD_RET_USAGE;
> +
> +	ifname = argv[1];
> +	dev = argv[2];
> +	file = argv[3];
> +
> +	// check file exists
> +	if (fs_set_blk_dev(ifname, dev, FS_TYPE_ANY))
> +		return CMD_RET_FAILURE;
> +
> +	if (!fs_exists(file)) {
> +		log_err("File does not exist: ifname=%s dev=%s file=%s\n", ifname, dev, file);
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	// get file size
> +	if (fs_set_blk_dev(ifname, dev, FS_TYPE_ANY))
> +		return CMD_RET_FAILURE;
> +
> +	if (fs_size(file, &file_size)) {
> +		log_err("Cannot read file size: ifname=%s dev=%s file=%s\n", ifname, dev, file);
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	// allocate memory for file content
> +	buffer = calloc(sizeof(char), file_size + 1);
> +	if (!buffer) {
> +		log_err("Out of memory\n");
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	// map pointer to system memory
> +	buffer_sysmem_addr = map_to_sysmem(buffer);
> +
> +	// read file to memory
> +	if (fs_set_blk_dev(ifname, dev, FS_TYPE_ANY))
> +		return CMD_RET_FAILURE;
> +
> +	if (fs_read(file, buffer_sysmem_addr, 0, 0, &file_size)) {
> +		log_err("Cannot read file: ifname=%s dev=%s file=%s\n", ifname, dev, file);
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	// unmap system memory
> +	unmap_sysmem(buffer);
> +
> +	// print file content
> +	buffer[file_size] = '\0';
> +	puts(buffer);
> +
> +	free(buffer);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_SYS_LONGHELP
> +static char cat_help_text[] =
> +	"<interface> <dev[:part]> <file>\n"
> +	"  - Print file from 'dev' on 'interface' to standard output\n";
> +#endif
> +
> +U_BOOT_CMD(cat, 4, 1, do_cat,
> +	   "Print file to standard output",
> +	   cat_help_text
> +);
> diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
> index 6553568e76..b2c9f19f11 100644
> --- a/configs/sandbox64_defconfig
> +++ b/configs/sandbox64_defconfig
> @@ -22,6 +22,7 @@ CONFIG_CONSOLE_RECORD=y
>   CONFIG_CONSOLE_RECORD_OUT_SIZE=0x1000
>   CONFIG_PRE_CONSOLE_BUFFER=y
>   CONFIG_DISPLAY_BOARDINFO_LATE=y
> +CONFIG_CMD_CAT=y
>   CONFIG_CMD_CPU=y
>   CONFIG_CMD_LICENSE=y
>   CONFIG_CMD_BOOTZ=y
> diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
> index eba7bcbb48..2136c76fe3 100644
> --- a/configs/sandbox_defconfig
> +++ b/configs/sandbox_defconfig
> @@ -36,6 +36,7 @@ CONFIG_LOG_DEFAULT_LEVEL=6
>   CONFIG_DISPLAY_BOARDINFO_LATE=y
>   CONFIG_STACKPROTECTOR=y
>   CONFIG_ANDROID_AB=y
> +CONFIG_CMD_CAT=y
>   CONFIG_CMD_CPU=y
>   CONFIG_CMD_LICENSE=y
>   CONFIG_CMD_BOOTM_PRE_LOAD=y
> diff --git a/doc/usage/cmd/cat.rst b/doc/usage/cmd/cat.rst
> new file mode 100644
> index 0000000000..5ef4731fe3
> --- /dev/null
> +++ b/doc/usage/cmd/cat.rst
> @@ -0,0 +1,49 @@
> +.. SPDX-License-Identifier: GPL-2.0+:
> +
> +cat command
> +===============
> +
> +Synopsis
> +--------
> +
> +::
> +
> +    cat <interface> <dev[:part]> <file>
> +
> +Description
> +-----------
> +
> +The cat command prints the file content to standard out.
> +
> +interface
> +    interface for accessing the block device (mmc, sata, scsi, usb, ....)
> +
> +dev
> +    device number
> +
> +part
> +    partition number, defaults to 1
> +
> +file
> +    path to file
> +
> +Example
> +-------
> +
> +Here is the output for a example text file:
> +
> +::
> +
> +    => cat mmc 0:1 hello
> +    hello world
> +    =>
> +
> +Configuration
> +-------------
> +
> +The cat command is only available if CONFIG_CMD_CAT=y.
> +
> +Return value
> +------------
> +
> +The return value $? is set to 0 (true) if the file is readable, otherwise it returns a non-zero error code.
> diff --git a/test/py/tests/test_cat/conftest.py b/test/py/tests/test_cat/conftest.py
> new file mode 100644
> index 0000000000..426f64485f
> --- /dev/null
> +++ b/test/py/tests/test_cat/conftest.py
> @@ -0,0 +1,33 @@
> +# SPDX-License-Identifier:      GPL-2.0+
> +
> +"""Fixture for cat command test
> +"""
> +
> +import os
> +import shutil
> +from subprocess import check_call
> +import pytest
> +
> + at pytest.fixture(scope='session')
> +def cat_data(u_boot_config):
> +    """Set up a file system to be used in cat tests
> +
> +    Args:
> +        u_boot_config -- U-boot configuration.
> +
> +    Return:
> +        A path to disk image to be used for testing
> +    """
> +    mnt_point = u_boot_config.persistent_data_dir + '/test_cat'
> +    image_path = u_boot_config.persistent_data_dir + '/cat.img'
> +
> +    shutil.rmtree(mnt_point, ignore_errors=True)
> +    os.mkdir(mnt_point, mode = 0o755)
> +
> +    with open(mnt_point + '/hello', 'w', encoding = 'ascii') as file:
> +        file.write('hello world\n')
> +
> +    check_call(f'virt-make-fs --partition=gpt --size=+1M --type=vfat {mnt_point} {image_path}',
> +               shell=True)

Best practice is to remove test data after usage. You could follow this
pattern:

@pytest.fixture()
def resource():
     print("setup")
     yield "resource"
     print("teardown")

See
https://docs.pytest.org/en/latest/how-to/fixtures.html#teardown-cleanup-aka-fixture-finalization

virt-make-fs fails if the user has no read access to the kernel. So you
should handle CalledProcessError like in test/py/tests/test_fs/conftest.py

> +
> +    return image_path
> diff --git a/test/py/tests/test_cat/test_cat.py b/test/py/tests/test_cat/test_cat.py
> new file mode 100644
> index 0000000000..41ddefa40c
> --- /dev/null
> +++ b/test/py/tests/test_cat/test_cat.py
> @@ -0,0 +1,22 @@
> +# SPDX-License-Identifier:      GPL-2.0+
> +
> +""" Unit test for cat command
> +"""
> +
> +import pytest
> +
> + at pytest.mark.boardspec('sandbox')
> + at pytest.mark.buildconfigspec('cmd_cat')
> +def test_cat(u_boot_console, cat_data):
> +    """ Unit test for cat
> +
> +    Args:
> +        u_boot_console -- U-Boot console
> +        cat_data -- Path to the disk image used for testing.
> +    """
> +    u_boot_console.run_command(cmd = f'host bind 0 {cat_data}')
> +
> +    response = u_boot_console.run_command(cmd = 'cat host 0 hello')
> +    assert 'hello world' == response
> +
> +    u_boot_console.run_command(cmd = 'exit', wait_for_echo=False)

As Simon already indicated this line should be removed.

Best regards

Heinrich

> --
> 2.25.1
>
>



More information about the U-Boot mailing list