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Property:let (bashcmd)

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Name-Collision - multiple objects in this wiki use the name let!
let (bashcmd) Evaluate arithmetic expressions.
let (bbcmd) Perform arithmetic on shell variables.

Bash-Command

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Details

Excerpt from:   Bash source   >>   let command

Possible #if / #endif blocks are compile options. There is no mechanism yet on BoxMatrix to detect which of these are set per model.

let arg [arg ...]

Evaluate arithmetic expressions.

Evaluate each ARG as an arithmetic expression.  Evaluation is done in
fixed-width integers with no check for overflow, though division by 0
is trapped and flagged as an error.  The following list of operators is
grouped into levels of equal-precedence operators.  The levels are listed
in order of decreasing precedence.

    id++, id--    variable post-increment, post-decrement
    ++id, --id    variable pre-increment, pre-decrement
    -, +        unary minus, plus
    !, ~        logical and bitwise negation
    **        exponentiation
    *, /, %        multiplication, division, remainder
    +, -        addition, subtraction
    <<, >>        left and right bitwise shifts
    <=, >=, <, >    comparison
    ==, !=        equality, inequality
    &        bitwise AND
    ^        bitwise XOR
    |        bitwise OR
    &&        logical AND
    ||        logical OR
    expr ? expr : expr
            conditional operator
    =, *=, /=, %=,
    +=, -=, <<=, >>=,
    &=, ^=, |=    assignment

Shell variables are allowed as operands.  The name of the variable
is replaced by its value (coerced to a fixed-width integer) within
an expression.  The variable need not have its integer attribute
turned on to be used in an expression.

Operators are evaluated in order of precedence.  Sub-expressions in
parentheses are evaluated first and may override the precedence
rules above.

Exit Status:
If the last ARG evaluates to 0, let returns 1; let returns 0 otherwise.

Excerpt from:   bashref.info   >>   Bash Builtins   >>   let command

let EXPRESSION [EXPRESSION ...]

The 'let' builtin allows arithmetic to be performed on shell
variables.  Each EXPRESSION is evaluated according to the rules
given below in *note Shell Arithmetic::.  If the last EXPRESSION
evaluates to 0, 'let' returns 1; otherwise 0 is returned.

Excerpt from:   bashref.info   >>   Shell Arithmetic   >>   let command

Shell Arithmetic

The shell allows arithmetic expressions to be evaluated, as one of the
shell expansions or by using the '((' compound command, the 'let'
builtin, or the '-i' option to the 'declare' builtin.

Evaluation is done in fixed-width integers with no check for
overflow, though division by 0 is trapped and flagged as an error.  The
operators and their precedence, associativity, and values are the same
as in the C language.  The following list of operators is grouped into
levels of equal-precedence operators.  The levels are listed in order of
decreasing precedence.

ID++ ID--
  variable post-increment and post-decrement

++ID --ID
  variable pre-increment and pre-decrement

- +
  unary minus and plus

! ~
  logical and bitwise negation

**
  exponentiation

* / %
  multiplication, division, remainder

+ -
  addition, subtraction

<< >>
  left and right bitwise shifts

<= >= < >
  comparison

== !=
  equality and inequality

&
  bitwise AND

^
  bitwise exclusive OR

|
  bitwise OR

&&
  logical AND

||
  logical OR

expr ? expr : expr
  conditional operator

= *= /= %= += -= <<= >>= &= ^= |=
  assignment

expr1 , expr2
  comma

Shell variables are allowed as operands; parameter expansion is
performed before the expression is evaluated.  Within an expression,
shell variables may also be referenced by name without using the
parameter expansion syntax.  A shell variable that is null or unset
evaluates to 0 when referenced by name without using the parameter
expansion syntax.  The value of a variable is evaluated as an arithmetic
expression when it is referenced, or when a variable which has been
given the INTEGER attribute using 'declare -i' is assigned a value.  A
null value evaluates to 0.  A shell variable need not have its INTEGER
attribute turned on to be used in an expression.

Constants with a leading 0 are interpreted as octal numbers.  A
leading '0x' or '0X' denotes hexadecimal.  Otherwise, numbers take the
form [BASE'#']N, where the optional BASE is a decimal number between 2
and 64 representing the arithmetic base, and N is a number in that base.
If BASE'#' is omitted, then base 10 is used.  When specifying N, the
digits greater than 9 are represented by the lowercase letters, the
uppercase letters, '@', and '_', in that order.  If BASE is less than or
equal to 36, lowercase and uppercase letters may be used interchangeably
to represent numbers between 10 and 35.

Operators are evaluated in order of precedence.  Sub-expressions in
parentheses are evaluated first and may override the precedence rules
above.

GPL-Browser

Daily updated index of all let code findings on the GPL-Browser. Last update: 2024-12-23 05:02 GMT.
The Browse column points to the Path containing the respective source code on the gpl.boxmatrix.info service.
The SoC column lists the Chip-Codenames, the Model column lists the nicks of the Box-Models.
The Diff column links the comparison of the AVM Kernel to the pristine original from Kernel.org.
The Download column links the full tarball the respective directory content is extracted from.
The presence of the source does not mean it fits the respective model and architecture. See the Model-Matrix where it's used.

Dependencies

Daily updated index of all dependencies of this command. Last update: 2024-12-23 07:59 GMT.
A * in the Mod column marks info from Supportdata-Probes, which will always stay incomplete.

Relation Typ Object Mod Firmware Info Origin
0 dependencies for this command

Model-Matrix

Daily updated index of the presence, path and size of this command for each model. Last update: 2024-12-23 05:43 GMT.
Showing all models using this command. Click any column header (click-wait-click) to sort the list by the respective data.
The (main/scrpn/boot/arm/prx/atom/rtl) label in the Model column shows which CPU is meant for Multi-Linux models.
Note that this list is merged from Firmware-Probes of all known AVM firmware for a model, including Recovery.exe and Labor-Files.

Model Firmware Path Size
FRITZ!Box 6591 Cable (atom) 7.04 - 8.00 <bash>
FRITZ!Box 6660 Cable (atom) 7.14 - 8.00 <bash>
FRITZ!Box 6670 Cable (atom) 7.61 - 7.90 <bash>
FRITZ!Box 6690 Cable (atom) 7.28 - 7.90 <bash>
4 models use this command

Symbols

Daily updated index of all symbols of this command. Last update: 2024-12-23 07:59 GMT.

Firmware Symbol
0 symbols for this command

SMW-Browser

Information is currently being retrieved from the backend.