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1.. SPDX-License-Identifier: GPL-2.0+
2
3.. index::
4 single: itest (command)
5
6itest command
7=============
8
9Synopsis
10--------
11
12::
13
14 itest[.b | .w | .l | .q | .s] [*]<value1> <op> [*]<value2>
15
16Description
17-----------
18
19The itest command is used to compare two values. The return value $? is set
20accordingly.
21
22By default it is assumed that the values are 4 byte integers. By appending a
23postfix (.b, .w, .l, .q, .s) the size can be specified:
24
25======= ======================================================
26postfix meaning
27======= ======================================================
28.b 1 byte integer
29.w 2 byte integer
30.l 4 byte integer
31.q 8 byte integer (only available if CONFIG_PHYS_64BIT=y)
32.s string
33======= ======================================================
34
35value1, value2
36 values to compare. Numeric values are hexadecimal. If '*' is prefixed a
37 hexadecimal address is passed, which points to the value to be compared.
38
39op
40 operator, see table
41
42 ======== ======================
43 operator meaning
44 ======== ======================
45 -lt less than
46 < less than
47 -le less or equal
48 <= less or equal
49 -eq equal
50 == equal
51 -ne not equal
52 != not equal
53 <> not equal
54 -ge greater or equal
55 >= greater or equal
56 -gt greater than
57 > greater than
58 ======== ======================
59
60Examples
61--------
62
63The itest command sets the result variable $? to true (0) or false (1):
64
65::
66
67 => itest 3 < 4; echo $?
68 0
69 => itest 3 == 4; echo $?
70 1
71
72This value can be used in the :doc:`if <if>` command:
73
74::
75
76 => if itest 0x3002 < 0x4001; then echo true; else echo false; fi
77 true
78
79Numbers will be truncated according to the postfix before comparing:
80
81::
82
83 => if itest.b 0x3002 < 0x4001; then echo true; else echo false; fi
84 false
85
86Postfix .s causes a string compare. The string '0xa1234' is alphabetically
87smaller than '0xb'.
88
89::
90
91 => if itest.s 0xa1234 < 0xb; then echo true; else echo false; fi
92 true
93
94A value prefixed by '*' is a pointer to the value in memory.
95
96::
97
98 => mm 0x4000
99 00004000: 00000004 ?
100 00004004: 00000003 ? =>
101 => if itest *0x4000 == 4; then echo true; else echo false; fi
102 true
103 => if itest *0x4004 == 3; then echo true; else echo false; fi
104 true
105
106Configuration
107-------------
108
109The command is only available if CONFIG_CMD_ITEST=y.
110
111Return value
112------------
113
114The return value $? is 0 (true) if the condition is true and 1 (false)
115otherwise.