u-boot/common/cmd_setexpr.c
Wolfgang Denk a89c33db96 General help message cleanup
Many of the help messages were not really helpful; for example, many
commands that take no arguments would not print a correct synopsis
line, but "No additional help available." which is not exactly wrong,
but not helpful either.

Commit ``Make "usage" messages more helpful.'' changed this
partially. But it also became clear that lots of "Usage" and "Help"
messages (fields "usage" and "help" in struct cmd_tbl_s respective)
were actually redundant.

This patch cleans this up - for example:

Before:
	=> help dtt
	dtt - Digital Thermometer and Thermostat

	Usage:
	dtt         - Read temperature from digital thermometer and thermostat.

After:
	=> help dtt
	dtt - Read temperature from Digital Thermometer and Thermostat

	Usage:
	dtt

Signed-off-by: Wolfgang Denk <wd@denx.de>
2009-06-12 20:47:16 +02:00

70 lines
2 KiB
C

/*
* Copyright 2008 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* This file provides a shell like 'expr' function to return.
*/
#include <common.h>
#include <config.h>
#include <command.h>
int do_setexpr(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
ulong a, b;
char buf[16];
/* Validate arguments */
if ((argc != 5) || (strlen(argv[3]) != 1)) {
cmd_usage(cmdtp);
return 1;
}
a = simple_strtoul(argv[2], NULL, 16);
b = simple_strtoul(argv[4], NULL, 16);
switch (argv[3][0]) {
case '|': sprintf(buf, "%lx", (a | b)); break;
case '&': sprintf(buf, "%lx", (a & b)); break;
case '+': sprintf(buf, "%lx", (a + b)); break;
case '^': sprintf(buf, "%lx", (a ^ b)); break;
case '-': sprintf(buf, "%lx", (a - b)); break;
case '*': sprintf(buf, "%lx", (a * b)); break;
case '/': sprintf(buf, "%lx", (a / b)); break;
case '%': sprintf(buf, "%lx", (a % b)); break;
default:
printf("invalid op\n");
return 1;
}
setenv(argv[1], buf);
return 0;
}
U_BOOT_CMD(
setexpr, 5, 0, do_setexpr,
"set environment variable as the result of eval expression",
"name value1 <op> value2\n"
" - set environment variable 'name' to the result of the evaluated\n"
" express specified by <op>. <op> can be &, |, ^, +, -, *, /, %"
);