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