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[bash/en] Add arrays and alias

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Neinei0k 2017-11-14 19:30:57 +00:00 committed by GitHub
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@ -83,6 +83,25 @@ echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"}
# This works for null (Foo=) and empty string (Foo=""); zero (Foo=0) returns 0.
# Note that it only returns default value and doesn't change variable value.
# Declare an array with 6 elements
array0=(one two three four five six)
# Print first element
echo $array0 # => "one"
# Print first element
echo ${array0[0]} # => "one"
# Print all elements
echo ${array0[@]} # => "one two three four five six"
# Print number of elements
echo ${#array0[@]} # => "6"
# Print number of characters in third element
echo ${#array0[2]} # => "5"
# Print 2 elements starting from forth
echo ${array0[@]:3:2} # => "four five"
# Print all elements. Each of them on new line.
for i in "${array0[@]}"; do
echo "$i"
done
# Brace Expansion { }
# Used to generate arbitrary strings
echo {1..10} # => 1 2 3 4 5 6 7 8 9 10
@ -155,6 +174,13 @@ then
echo "This will run if $Name is Daniya OR Zach."
fi
# Redefine command 'ping' as alias to send only 5 packets
alias ping='ping -c 5'
# Escape alias and use command with this name instead
\ping 192.168.1.1
# Print all aliases
alias -p
# Expressions are denoted with the following format:
echo $(( 10 + 5 )) # => 15