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#!/bin/bash
# Counting to 11 in 10 different ways.
n=1; echo -n "$n "
let "n = $n + 1" # let "n = n + 1" also works.
echo -n "$n "
: $((n = $n + 1))
# ":" necessary because otherwise Bash attempts
#+ to interpret "$((n = $n + 1))" as a command.
echo -n "$n "
(( n = n + 1 ))
# A simpler alternative to the method above.
# Thanks, David Lombard, for pointing this out.
echo -n "$n "
n=$(($n + 1))
echo -n "$n "
: $[ n = $n + 1 ]
# ":" necessary because otherwise Bash attempts
#+ to interpret "$[ n = $n + 1 ]" as a command.
# Works even if "n" was initialized as a string.
echo -n "$n "
n=$[ $n + 1 ]
# Works even if "n" was initialized as a string.
#* Avoid this type of construct, since it is obsolete and nonportable.
# Thanks, Stephane Chazelas.
echo -n "$n "
# Now for C-style increment operators.
# Thanks, Frank Wang, for pointing this out.
let "n++" # let "++n" also works.
echo -n "$n "
(( n++ )) # (( ++n )) also works.
echo -n "$n "
: $(( n++ )) # : $(( ++n )) also works.
echo -n "$n "
: $[ n++ ] # : $[ ++n ] also works
echo -n "$n "
echo
exit 0
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