Programming Forums > Script Programming > Bash / Shell Scripting

hush · Jun 17th, 2006, 2:30 PM

I script with ksh.

I run a script and this calls a couple of programs, these programs then request input for example:

Would you like to back up the table structure also (y/n)?

I�m not sure what language they are in.

What is it referred to in programming when I want to put input into these requests with a script rather then having to do it manually?

If I can find out this then I got a chance at googling it.

Thanks

hush

Arevos · Jun 17th, 2006, 2:47 PM

Not quite sure what you're asking. Most console scripts get input from the user via STDIN, and report back via STDOUT. You can pipe the STDOUT from one program to the STDIN of another by using pipes.

For example, the command "yes" outputs a continual stream of identical lines. By default, it's "y". Thus, by piping "yes" to a different program, you can get it to answer "y" to every question posed:

(Toggle Plain Text)

yes | some_program

If you want something more complex, then you can pipe a file in:

(Toggle Plain Text)

some_file > some_program

Or create some program of your own to generate the output.

hush · Jun 18th, 2006, 7:23 AM

Thanks for the reply arevos.

Sorry I could not be clearer in my explanation.

I�m aware of pipes.

What about if the program requests multiple standard inputs?

Could I use a file?

How would it be structured e.g would I use \n to move onto the next standard input?

I would have tried this but the unix box I use at work is a production system.

Is there another way to supply standard input; if so what is it called ? (this is the issue I was attempting to ask a question on in my first post)

hush

Arevos · Jun 18th, 2006, 11:20 AM

Your question isn't clear. There are multiple ways to input data into a program; via a GUI interface, via a TCP socket, via a file - the list goes on. The standard way of inputting data to console applications is STDIN, which most non-GUI console applications use. If you want to mix user input with automated input via STDIN in a custom arrangement, you'll probably need a more powerful scripting language than KSH. Possibly something like Perl or Python.

hush · Jun 18th, 2006, 2:19 PM

i found this:

http://en.wikipedia.org/wiki/Expect

what i was asking is not possible without a tool like this.

cheers anyway.

hush

jim mcnamara · Jun 19th, 2006, 9:00 AM

Do you know about the here document?

(Toggle Plain Text)

/path/to/myprogram $USER $PASS<<EOF
answer to question 1
output file filname
EOF

This is essentially what expect does. It knows the questions and answers ahead of time.

hush · Jun 21st, 2006, 4:50 PM

no, i will look into that cheers.

Jun 17th, 2006, 2:30 PM	#1
hush Programmer Join Date: Feb 2006 Location: 127.0.0.1 Posts: 35 Rep Power: 0	what is this called I script with ksh. I run a script and this calls a couple of programs, these programs then request input for example: Would you like to back up the table structure also (y/n)? I�m not sure what language they are in. What is it referred to in programming when I want to put input into these requests with a script rather then having to do it manually? If I can find out this then I got a chance at googling it. Thanks hush

Jun 17th, 2006, 2:47 PM	#2
Arevos Programming Guru Join Date: Aug 2005 Location: England Posts: 1,499 Rep Power: 4	Not quite sure what you're asking. Most console scripts get input from the user via STDIN, and report back via STDOUT. You can pipe the STDOUT from one program to the STDIN of another by using pipes. For example, the command "yes" outputs a continual stream of identical lines. By default, it's "y". Thus, by piping "yes" to a different program, you can get it to answer "y" to every question posed: (Toggle Plain Text) yes \| some_program yes \| some_program If you want something more complex, then you can pipe a file in: (Toggle Plain Text) some_file > some_program some_file > some_program Or create some program of your own to generate the output.

Jun 19th, 2006, 9:00 AM	#6
jim mcnamara Hobbyist Programmer Join Date: Jun 2005 Location: New Mexico Posts: 228 Rep Power: 4	Do you know about the here document? (Toggle Plain Text) /path/to/myprogram $USER $PASS<<EOF answer to question 1 output file filname EOF /path/to/myprogram $USER $PASS<<EOF answer to question 1 output file filname EOF This is essentially what expect does. It knows the questions and answers ahead of time.

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Jun 18th, 2006, 7:23 AM	#3
hush Programmer Join Date: Feb 2006 Location: 127.0.0.1 Posts: 35 Rep Power: 0	Thanks for the reply arevos. Sorry I could not be clearer in my explanation. I�m aware of pipes. What about if the program requests multiple standard inputs? Could I use a file? How would it be structured e.g would I use \n to move onto the next standard input? I would have tried this but the unix box I use at work is a production system. Is there another way to supply standard input; if so what is it called ? (this is the issue I was attempting to ask a question on in my first post) hush

Jun 18th, 2006, 11:20 AM	#4
Arevos Programming Guru Join Date: Aug 2005 Location: England Posts: 1,499 Rep Power: 4	Your question isn't clear. There are multiple ways to input data into a program; via a GUI interface, via a TCP socket, via a file - the list goes on. The standard way of inputting data to console applications is STDIN, which most non-GUI console applications use. If you want to mix user input with automated input via STDIN in a custom arrangement, you'll probably need a more powerful scripting language than KSH. Possibly something like Perl or Python.

Jun 18th, 2006, 2:19 PM	#5
hush Programmer Join Date: Feb 2006 Location: 127.0.0.1 Posts: 35 Rep Power: 0	i found this: http://en.wikipedia.org/wiki/Expect what i was asking is not possible without a tool like this. cheers anyway. hush

Jun 21st, 2006, 4:50 PM	#7
hush Programmer Join Date: Feb 2006 Location: 127.0.0.1 Posts: 35 Rep Power: 0	no, i will look into that cheers.

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Programming Forums > Script Programming > Bash / Shell Scripting

what is this called