U-Boot. Команды оболочки: for
for command
===========
Synopis
-------
::
for <variable> in <items>; do <commands>; done
Description
-----------
The for command is used to loop over a list of values and execute a series of
commands for each of these.
The counter variable of the loop is a shell variable. Please, keep in mind that
an environment variable takes precedence over a shell variable of the same name.
variable
name of the counter variable
items
space separated item list
commands
commands to execute
Example
-------
::
=> setenv c
=> for c in 1 2 3; do echo item ${c}; done
item 1
item 2
item 3
=> echo ${c}
3
=> setenv c x
=> for c in 1 2 3; do echo item ${c}; done
item x
item x
item x
=>
The first line ensures that there is no environment variable *c*. Hence in the
first loop the shell variable *c* is printed.
After defining an environment variable of name *c* it takes precedence over the
shell variable and the environment variable is printed.
Return value
------------
The return value $? after the done statement is the return value of the last
statement executed in the loop.
::
=> for i in true false; do ${i}; done; echo $?
1
=> for i in false true; do ${i}; done; echo $?
0