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.. SPDX-License-Identifier: GPL-2.0+
.. index::
single: itest (command)
itest command
=============
Synopsis
--------
::
itest[.b | .w | .l | .q | .s] [*]<value1> <op> [*]<value2>
Description
-----------
The itest command is used to compare two values. The return value $? is set
accordingly.
By default it is assumed that the values are 4 byte integers. By appending a
postfix (.b, .w, .l, .q, .s) the size can be specified:
======= ======================================================
postfix meaning
======= ======================================================
.b 1 byte integer
.w 2 byte integer
.l 4 byte integer
.q 8 byte integer (only available if CONFIG_PHYS_64BIT=y)
.s string
======= ======================================================
value1, value2
values to compare. Numeric values are hexadecimal. If '*' is prefixed a
hexadecimal address is passed, which points to the value to be compared.
op
operator, see table
======== ======================
operator meaning
======== ======================
-lt less than
< less than
-le less or equal
<= less or equal
-eq equal
== equal
-ne not equal
!= not equal
<> not equal
-ge greater or equal
>= greater or equal
-gt greater than
> greater than
======== ======================
Examples
========
The itest command sets the result variable $? to true (0) or false (1):
::
=> itest 3 < 4; echo $?
0
=> itest 3 == 4; echo $?
1
This value can be used in the :doc:`if <if>` command:
::
=> if itest 0x3002 < 0x4001; then echo true; else echo false; fi
true
Numbers will be truncated according to the postfix before comparing:
::
=> if itest.b 0x3002 < 0x4001; then echo true; else echo false; fi
false
Postfix .s causes a string compare. The string '0xa1234' is alphabetically
smaller than '0xb'.
=> if itest.s 0xa1234 < 0xb; then echo true; else echo false; fi
true
A value prefixed by '*' is a pointer to the value in memory.
::
=> mm 0x4000
00004000: 00000004 ?
00004004: 00000003 ? =>
=> if itest *0x4000 == 4; then echo true; else echo false; fi
true
=> if itest *0x4004 == 3; then echo true; else echo false; fi
true
Configuration
-------------
The command is only available if CONFIG_CMD_ITEST=y.
Return value
------------
The return value $? is 0 (true) if the condition is true and 1 (false)
otherwise.
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