Restart loop from the previous state if a condition is not met - bash

Question

The problem statement is that if a condition is not true, it should "stop" the for loop or should not progress unless that value is met.
Lets say that there is an input statement of true/false or a boolean statement in a for loop that prints to 1 to 10.
If the condition goes false in the the 5th iteration, it should stay at 5th iteration until the boolean returns true.
for i in {1..10}
do
read jobstatus
# echo $i
if [ "$jobstatus" = true ] ; then
echo 'Okay lets progress'
else
echo 'Nop, cant progress'
((i--))
# continue
#print $i
fi
echo $i
done
I have tried making codes such as this, also checked it via making files that were acting as "flags" But I cant seem to "stop" the progression. I dont want to break the loop, I just want to make it stay at that specific iteration until and unless the state changes.
Like if the job status goes falses at i=5, i should stay at 5 unless jobstatus gets to true. ( I intend to check the jobstatus at each input)

Answer 1

You could structure the loops something like:
#!/bin/bash
i=0
while test "$i" -lt 10; do
while read jobstatus && test "$jobstatus" != true; do
echo "can't progress. jobstatus = $jobstatus" >&2
done
if test "$jobstatus" = true; then
echo "Okay lets progress to step $((++i))"
else
echo Unexpected End of input >&2
exit 1
fi
echo "$i"
done

Answer 2

Use a C-style for-loop:
#!/bin/bash
for ((i=1; i<=10; ++i)) ; do
read jobstatus
if [ "$jobstatus" = true ] ; then
echo 'Okay lets progress'
else
echo 'Nop, cant progress'
((i--))
fi
echo $i
done

Answer 3

The if test should to be a loop of some sort.
For example:
for i in {1..10}
do
while
read jobstatus
[ "$jobstatus" != true ]
do
echo 'Nop, cant progress'
done
echo 'Okay lets progress'
echo $i
done
If you want to repeat the other for commands (ie. the echo $i statement here) until the test succeeds, they should go inside the loop too. For example:
for i in {1..10}
do
while
echo $i
read jobstatus
[ "$jobstatus" != true ]
do
echo 'Nop, cant progress'
done
echo 'Okay lets progress'
done

Answer 4

This may be what you are looking for:
for i in {1..10}; do
read jobstatus
if [ "$jobstatus" != true ]; then
echo 'Nop, cant progress'
fi
while [ "$jobstatus" != "true" ]; do
read jobstatus
sleep 1
# echo statements here if needed
done
echo 'Okay lets progress'
echo $i
done
No need to decrement i , this also avoids checking the status of jobstatus too often potentially consuming an unnecessary amount of resources.

Answer 5

With an interactive user input, Maybe something like this:
#!/bin/sh
i=0
while [ "$i" -lt 10 ] && printf 'Enter status: '; do
IFS= read -r jobstatus
case "$jobstatus" in
true)
i=$((i+1))
printf 'Okay lets progress to %s' "$i";;
*)
printf >&2 'Nop, cant progress because jobstatus is: %s' "${jobstatus:-empty}"
esac
printf '\n'
done
Using a text file for the input, to test the script.
The file.txt
true
true
true
true
true
false
foo
bar
baz
true
true
true
true
qux
true
false
The script:
#!/bin/sh
i=0
while [ "$i" -lt 10 ] && IFS= read -r jobstatus; do
case "$jobstatus" in
true)
i=$((i+1))
printf 'Okay lets progress to %s' "$i";;
*)
printf >&2 'Nop, cant progress because jobstatus is: %s' "${jobstatus:-empty}";;
esac
printf '\n'
done < file.txt
Output:
Okay lets progress to 1
Okay lets progress to 2
Okay lets progress to 3
Okay lets progress to 4
Okay lets progress to 5
Nop, cant progress because jobstatus is: false
Nop, cant progress because jobstatus is: foo
Nop, cant progress because jobstatus is: bar
Nop, cant progress because jobstatus is: baz
Nop, cant progress because jobstatus is: empty
Okay lets progress to 6
Okay lets progress to 7
Okay lets progress to 8
Okay lets progress to 9
Nop, cant progress because jobstatus is: qux
Nop, cant progress because jobstatus is: empty
Okay lets progress to 10

Answer 6

Try this Shellcheck-clean Bash code:
#! /bin/bash -p
for ((truecount=0; truecount<10;)); do
read -r jobstatus
if [[ $jobstatus == true ]]; then
echo "Okay let's progress"
(( ++truecount ))
else
echo "Nope, can't progress"
fi
printf '%d\n' "$truecount"
done
The major change from the original code is that it advances only on 'true' status instead of always advancing and stepping back on non-'true' status. In general, it's best if you can modify a loop variable in only one place.
Since the code isn't just stepping through a sequence, I replaced the meaningless i with the descriptive truecount.
See the accepted, and excellent, answer to Why is printf better than echo? for an explanation of why I used printf instead of echo to print the count value. (echo "$truecount" would probably be OK in this specific case, but echo "$var" doesn't work in general so I never use it. echo $var is bad. See Bash Pitfalls #14 (echo $foo).)