Unix Pipe problem

[bjdobs]

My understanding of pipe is that if one creates a text file of commands for example menu commands for an application
then it can be piped to the application to automate it.

app < TextFileWithCmds.txt

assume asp has a 3 level menu where we would want to go to level 3 and enter in a set of info which never changes:

x
m
2
9
arcst
/usr/acct/arcst.txt
q


x

When I enter this data into a file then use the pipe method it appears the app throws this all away and just hangs on the first step.

I also tried cat TextFileWithCmds.txt | app


Am I missing something or is the application just not using standard I/O properly (maybe on purpose)?

 

[olded]

Hi:

Your comment:

... can be piped to the application to automate it.

is not necessarily correct. app may not be written as a pipe.

Your redirection example should work:

pp < TextFileWithCmds.txt

provided you've set up your data file correctly. You can eliminate the file itself by using the unix &quot;here&quot; document facility:

app << MSG
x
m
2
9
arcst
/usr/acct/arcst.txt
q


x
MSG

If you've never used a here document, app reads input up to the second MSG tag. It's important it be in column 1. If you want to redirect standard output of app:

app << MSG > output.file
.
.
MSG

Regards,

Ed

 

[jamisar]

echo &quot;3*77/12&quot; | bc
this is a pipe because 'bc' is able to read stdin, what does your 'app'