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

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)

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

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

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

</details>



# 答案4
**得分**: 0

这可能是您正在寻找的内容：

```bash
for i in {1..10}; do
  read jobstatus
  if [ "$jobstatus" != true ]; then
    echo '不行，无法继续'
  fi

  while [ "$jobstatus" != "true" ]; do
    read jobstatus
    sleep 1
    # 如果需要，可以在这里添加 echo 语句
  done

  echo '好的，让我们继续'
  echo $i
done

无需减少 i，这也避免了过于频繁地检查 jobstatus 状态，从而节省了不必要的资源。

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

答案5

得分: 0

以下是代码的翻译部分：

#!/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

#!/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

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

#!/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

true
true
true
true
true
false
foo
bar
baz

true
true
true
true
qux

true
false

#!/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

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

答案6

得分: 0

请尝试这个经过 Shellcheck 清理过的 Bash 代码：

#! /bin/bash -p

for ((truecount=0; truecount<10;)); do
    read -r jobstatus
    if [[ $jobstatus == true ]]; then
        echo "好的，让我们继续"
        (( ++truecount ))
    else
        echo "不行，无法继续"
    fi
    printf '%d\n' "$truecount"
done

• 与原始代码的主要变化是它只在 'true' 状态下前进，而不是总是前进并在非 'true' 状态下后退。一般来说，最好只在一个地方修改循环变量。
• 由于代码不仅仅是在一个序列中前进，我用有描述性的 'truecount' 替代了无意义的 'i'。
• 请参考 为什么 printf 比 echo 好？ 中的已被接受和优秀的答案，以了解为什么我使用 printf 而不是 echo 来打印计数值。 (echo "$truecount" 在这种特定情况下可能也可以，但 echo "$var" 在一般情况下不起作用，因此我从不使用它。 echo $var 是有问题的。请参阅 Bash 陷阱 #14 (echo $foo)。)

#! /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