BASH: how to view command history in while loop?

up vote
5
down vote

favorite

2

I have a simple while loop accepting input:

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    echo "$userInput"

done

Example:

./input.sh 



 username> command1

command1



 username> command2

command2

Is it possible to have a command history? So that I can press up on my keyboard to view the previously executed commands (without leaving the while loop)?

linux bash shell-script shell ubuntu

share|improve this question

asked 20 hours ago

user321630

362

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user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment | 

up vote
5
down vote

favorite

2

I have a simple while loop accepting input:

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    echo "$userInput"

done

Example:

./input.sh 



 username> command1

command1



 username> command2

command2

Is it possible to have a command history? So that I can press up on my keyboard to view the previously executed commands (without leaving the while loop)?

linux bash shell-script shell ubuntu

share|improve this question

asked 20 hours ago

user321630

362

New contributor

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

up vote
5
down vote

favorite

2

up vote
5
down vote

favorite

2

2

I have a simple while loop accepting input:

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    echo "$userInput"

done

Example:

./input.sh 



 username> command1

command1



 username> command2

command2

Is it possible to have a command history? So that I can press up on my keyboard to view the previously executed commands (without leaving the while loop)?

linux bash shell-script shell ubuntu

share|improve this question

asked 20 hours ago

user321630

362

New contributor

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

I have a simple while loop accepting input:

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    echo "$userInput"

done

Example:

./input.sh 



 username> command1

command1



 username> command2

command2

Is it possible to have a command history? So that I can press up on my keyboard to view the previously executed commands (without leaving the while loop)?

linux bash shell-script shell ubuntu

linux bash shell-script shell ubuntu

share|improve this question

asked 20 hours ago

user321630

362

New contributor

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

asked 20 hours ago

user321630

362

New contributor

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

share|improve this question

asked 20 hours ago

user321630

362

New contributor

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 20 hours ago

user321630

362

asked 20 hours ago

user321630

362

362

New contributor

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

New contributor

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

user321630 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

add a comment | 

2 Answers
2

active

oldest

votes

up vote
8
down vote



accepted

You could use the small Readline wrapper rlwrap. This is a neat little tool that provides command history to utilities that don't implement it by themselves.

You would use rlwrap on the script itself:

rlwrap -a ./script.sh

This would save a history file called ~/.script.sh_history and would use that file not only in the current session, but also in future sessions to provide a sort of history that you could step through.

See the manual for rlwrap.

rlwrap is commonly available as a package on most Unices, but may also be had from its GitHub repository.

share|improve this answer

edited 19 hours ago

answered 19 hours ago

Kusalananda

116k15218351

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Thanks for your answer. So this isn't possible purely with bash?
  – user321630
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @user321630 The read builtin does not provide this facility. You would have to implement it by saving the inputted data to a file and then somehow search that appropriately when the user uses the arrow keys.
  – Kusalananda
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Kusalananda I was thinking the same but is there any way to pass up-key as an argument? I searched a lot but no help.
  – Debian_yadav
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @Debian_yadav This is non-trivial as the up-arrow key sends a series of characters, and you would have to distinguish these from other input and to do that without requiring the user to press Enter. Here's the solution to the first part of that problem: bashscript to detect right arrow key being pressed
  – Kusalananda
  19 hours ago
  
  
  

  
  
  
  

add a comment | 

up vote
0
down vote

You can use history -s to edit the history list, and read -e to make it possible to view the history.

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    history -s "$userInput"

    echo "$userInput"

done

Note that there are various options about the command history. The behavior may be very different between a script and an interactive shell. For example, the command history is not loaded from or saved to a file automatically in a script, which may or may not be desirable in your situation. But you can fix it by adding more code if not.

share|improve this answer

answered 8 hours ago

user23013

457311

add a comment | 

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

active

oldest

votes

active

oldest

votes

up vote
8
down vote



accepted

You could use the small Readline wrapper rlwrap. This is a neat little tool that provides command history to utilities that don't implement it by themselves.

You would use rlwrap on the script itself:

rlwrap -a ./script.sh

This would save a history file called ~/.script.sh_history and would use that file not only in the current session, but also in future sessions to provide a sort of history that you could step through.

See the manual for rlwrap.

rlwrap is commonly available as a package on most Unices, but may also be had from its GitHub repository.

share|improve this answer

edited 19 hours ago

answered 19 hours ago

Kusalananda

116k15218351

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Thanks for your answer. So this isn't possible purely with bash?
  – user321630
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @user321630 The read builtin does not provide this facility. You would have to implement it by saving the inputted data to a file and then somehow search that appropriately when the user uses the arrow keys.
  – Kusalananda
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Kusalananda I was thinking the same but is there any way to pass up-key as an argument? I searched a lot but no help.
  – Debian_yadav
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @Debian_yadav This is non-trivial as the up-arrow key sends a series of characters, and you would have to distinguish these from other input and to do that without requiring the user to press Enter. Here's the solution to the first part of that problem: bashscript to detect right arrow key being pressed
  – Kusalananda
  19 hours ago
  
  
  

  
  
  
  

add a comment | 

up vote
8
down vote



accepted

You could use the small Readline wrapper rlwrap. This is a neat little tool that provides command history to utilities that don't implement it by themselves.

You would use rlwrap on the script itself:

rlwrap -a ./script.sh

This would save a history file called ~/.script.sh_history and would use that file not only in the current session, but also in future sessions to provide a sort of history that you could step through.

See the manual for rlwrap.

rlwrap is commonly available as a package on most Unices, but may also be had from its GitHub repository.

share|improve this answer

edited 19 hours ago

answered 19 hours ago

Kusalananda

116k15218351

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Thanks for your answer. So this isn't possible purely with bash?
  – user321630
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @user321630 The read builtin does not provide this facility. You would have to implement it by saving the inputted data to a file and then somehow search that appropriately when the user uses the arrow keys.
  – Kusalananda
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Kusalananda I was thinking the same but is there any way to pass up-key as an argument? I searched a lot but no help.
  – Debian_yadav
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @Debian_yadav This is non-trivial as the up-arrow key sends a series of characters, and you would have to distinguish these from other input and to do that without requiring the user to press Enter. Here's the solution to the first part of that problem: bashscript to detect right arrow key being pressed
  – Kusalananda
  19 hours ago
  
  
  

  
  
  
  

add a comment | 

up vote
8
down vote



accepted

up vote
8
down vote



accepted

You could use the small Readline wrapper rlwrap. This is a neat little tool that provides command history to utilities that don't implement it by themselves.

You would use rlwrap on the script itself:

rlwrap -a ./script.sh

This would save a history file called ~/.script.sh_history and would use that file not only in the current session, but also in future sessions to provide a sort of history that you could step through.

See the manual for rlwrap.

rlwrap is commonly available as a package on most Unices, but may also be had from its GitHub repository.

share|improve this answer

edited 19 hours ago

answered 19 hours ago

Kusalananda

116k15218351

You could use the small Readline wrapper rlwrap. This is a neat little tool that provides command history to utilities that don't implement it by themselves.

You would use rlwrap on the script itself:

rlwrap -a ./script.sh

This would save a history file called ~/.script.sh_history and would use that file not only in the current session, but also in future sessions to provide a sort of history that you could step through.

See the manual for rlwrap.

rlwrap is commonly available as a package on most Unices, but may also be had from its GitHub repository.

share|improve this answer

edited 19 hours ago

answered 19 hours ago

Kusalananda

116k15218351

share|improve this answer

share|improve this answer

edited 19 hours ago

edited 19 hours ago

edited 19 hours ago

answered 19 hours ago

Kusalananda

116k15218351

answered 19 hours ago

Kusalananda

116k15218351

answered 19 hours ago

Kusalananda

116k15218351

116k15218351

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Thanks for your answer. So this isn't possible purely with bash?
  – user321630
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @user321630 The read builtin does not provide this facility. You would have to implement it by saving the inputted data to a file and then somehow search that appropriately when the user uses the arrow keys.
  – Kusalananda
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Kusalananda I was thinking the same but is there any way to pass up-key as an argument? I searched a lot but no help.
  – Debian_yadav
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @Debian_yadav This is non-trivial as the up-arrow key sends a series of characters, and you would have to distinguish these from other input and to do that without requiring the user to press Enter. Here's the solution to the first part of that problem: bashscript to detect right arrow key being pressed
  – Kusalananda
  19 hours ago
  
  
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Thanks for your answer. So this isn't possible purely with bash?
  – user321630
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @user321630 The read builtin does not provide this facility. You would have to implement it by saving the inputted data to a file and then somehow search that appropriately when the user uses the arrow keys.
  – Kusalananda
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Kusalananda I was thinking the same but is there any way to pass up-key as an argument? I searched a lot but no help.
  – Debian_yadav
  19 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @Debian_yadav This is non-trivial as the up-arrow key sends a series of characters, and you would have to distinguish these from other input and to do that without requiring the user to press Enter. Here's the solution to the first part of that problem: bashscript to detect right arrow key being pressed
  – Kusalananda
  19 hours ago
  
  
  

  
  
  
  

Thanks for your answer. So this isn't possible purely with bash?
– user321630
19 hours ago

Thanks for your answer. So this isn't possible purely with bash?
– user321630
19 hours ago

@user321630 The read builtin does not provide this facility. You would have to implement it by saving the inputted data to a file and then somehow search that appropriately when the user uses the arrow keys.
– Kusalananda
19 hours ago

@user321630 The read builtin does not provide this facility. You would have to implement it by saving the inputted data to a file and then somehow search that appropriately when the user uses the arrow keys.
– Kusalananda
19 hours ago

@Kusalananda I was thinking the same but is there any way to pass up-key as an argument? I searched a lot but no help.
– Debian_yadav
19 hours ago

@Kusalananda I was thinking the same but is there any way to pass up-key as an argument? I searched a lot but no help.
– Debian_yadav
19 hours ago

1

1

@Debian_yadav This is non-trivial as the up-arrow key sends a series of characters, and you would have to distinguish these from other input and to do that without requiring the user to press Enter. Here's the solution to the first part of that problem: bashscript to detect right arrow key being pressed
– Kusalananda
19 hours ago

@Debian_yadav This is non-trivial as the up-arrow key sends a series of characters, and you would have to distinguish these from other input and to do that without requiring the user to press Enter. Here's the solution to the first part of that problem: bashscript to detect right arrow key being pressed
– Kusalananda
19 hours ago

add a comment | 

up vote
0
down vote

You can use history -s to edit the history list, and read -e to make it possible to view the history.

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    history -s "$userInput"

    echo "$userInput"

done

Note that there are various options about the command history. The behavior may be very different between a script and an interactive shell. For example, the command history is not loaded from or saved to a file automatically in a script, which may or may not be desirable in your situation. But you can fix it by adding more code if not.

share|improve this answer

answered 8 hours ago

user23013

457311

add a comment | 

up vote
0
down vote

You can use history -s to edit the history list, and read -e to make it possible to view the history.

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    history -s "$userInput"

    echo "$userInput"

done

Note that there are various options about the command history. The behavior may be very different between a script and an interactive shell. For example, the command history is not loaded from or saved to a file automatically in a script, which may or may not be desirable in your situation. But you can fix it by adding more code if not.

share|improve this answer

answered 8 hours ago

user23013

457311

add a comment | 

up vote
0
down vote

up vote
0
down vote

You can use history -s to edit the history list, and read -e to make it possible to view the history.

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    history -s "$userInput"

    echo "$userInput"

done

Note that there are various options about the command history. The behavior may be very different between a script and an interactive shell. For example, the command history is not loaded from or saved to a file automatically in a script, which may or may not be desirable in your situation. But you can fix it by adding more code if not.

share|improve this answer

answered 8 hours ago

user23013

457311

You can use history -s to edit the history list, and read -e to make it possible to view the history.

#!/bin/bash

while true; do

    read -rep $'n '"$USER"'> ' userInput

    history -s "$userInput"

    echo "$userInput"

done

Note that there are various options about the command history. The behavior may be very different between a script and an interactive shell. For example, the command history is not loaded from or saved to a file automatically in a script, which may or may not be desirable in your situation. But you can fix it by adding more code if not.

share|improve this answer

answered 8 hours ago

user23013

457311

share|improve this answer

share|improve this answer

answered 8 hours ago

user23013

457311

answered 8 hours ago

user23013

457311

answered 8 hours ago

user23013

457311

457311

add a comment | 

add a comment | 

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