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I am probably just having a brain fart, but I can not for the life of me figure out how to loop through an array in shell script, not bash. Im sure the answer is on stackoverflow somewhere already, but I can not find a method of doing so without using bash. For my embedded target system bash is not currently an option. Here is an example of what I am attempting to do and the error that is returned.
#!/bin/sh
enable0=1
enable1=1
port=0
while [ ${port} -lt 2 ]; do
if [ ${enable${port}} -eq 1 ]
then
# do some stuff
fi
port=$((port + 1))
done
Whenever I run this script the error "Bad substitution" is returned for line with the if statement. If you guys have any ideas I would greatly appreciate it. Thanks!
642
There are two types of arrays that we can work with, in shell scripts. The default array that's created is an indexed array. If you specify the index names, it becomes an associative array and the elements can be accessed using the index names instead of numbers.
$1 means an input argument and -z means non-defined or empty. You're testing whether an input argument to the script was defined when running the script. Follow this answer to receive notifications.
An array can be created using array literal or Array constructor syntax. Array literal syntax: var stringArray = ["one", "two", "three"]; Array constructor syntax: var numericArray = new Array(3); A single array can store values of different data types.
a="abc 123 def"
set -- $a
while [ -n "$1" ]; do
echo $1
shift
done
Output via busybox 1.27.2 ash:
abc
123
def
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