Add a simple expr style command that will set an env variable as the result of the command. This allows us to do simple math in shell. The following operations are supported: &, |, ^, +, -, *, /. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>master
parent
0d48926c87
commit
d058698fd2
@ -0,0 +1,70 @@ |
|||||||
|
/*
|
||||||
|
* 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)) { |
||||||
|
printf("Usage:\n%s\n", cmdtp->usage); |
||||||
|
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, |
||||||
|
"setexpr - set environment variable as the result of eval expression\n", |
||||||
|
"name value1 <op> value2\n" |
||||||
|
" - set environment variable 'name' to the result of the evaluated\n" |
||||||
|
" express specified by <op>. <op> can be &, |, ^, +, -, *, /, %\n" |
||||||
|
); |
Loading…
Reference in new issue