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Loop

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While syntax ​

shell
while condition; do
  do_domething
done

For syntax ​

shell
for i in {1..10}; do
  echo $i
done

for MYVAR in val1 val2 val3; do
  echo $MYVAR
done

for path in folder/*/; do
  echo ${path}
  echo ${path%?}  # Remove last character
done

Examples ​

Loop until user signal:

shell
terminate=0
trap abort SIGUSR1

abort() {
  echo "Program has been aborted."
  terminate=1
}

while [[ terminate -eq 0 ]]; do
  stuff
done

Loop a variable using newline as separator.

shell
while IFS='' read -r line || [[ -n "${line}" ]]; do
  echo $line
done <<< "${message}"

Loop a variable using ; as separator (using IFS='' may add newline to the last variable).

shell
while read -rd ';' i || [[ -n "${i}" ]]; do
  echo "Value $i"
done <<< "1;2;3"