Very Computer

How can I invoke an interactive editor in a bash script after piping or
redirecting to it?  To illustrate, the script is (eg) vitest:

  #!/bin/bash
  SCRATCH=/tmp/scratch$$
  cat > SCRATCH
  vi SCRATCH

If I do

  bash$ vitest
  Hello
  <EOT>

all is well and I can edit the scratch file.  However, if I attempt to
use redirection, e.g.,

  bash$ echo Hello | vitest

or

  bash$ vitest < some.file.or.other

I get an

  Input read error

How can I get the redirection or piping to work the way I want it to,
without hacking ps and getting vi to connect explicitly to the terminal?
I feel sure I'm missing something really obvious, but none of the man
pages or FAQs seems to elucidate.

--
mv .sig /dev/null

Start vi with ''vi -'' if you want it to read from stdin.

  $ date | vi -

J?rgen

--
Chuck Geigner ---------------------------------------
AIX Sysop
Milner Library, Illinois State Univ.
"Been borrowing Occam's shaving instrument since 1992
Haven't cut myself yet."_____________#rgvac==mongoose

Because

  #!/bin/bash
  SCRATCH=/tmp/scratch$$
  cat > SCRATCH
  vi SCRATCH

doesn't work, but the above with (e.g.)

  vi SCRATCH < /dev/pts/45

does work (on SunOS at least).  The relevant tty data is grepped from
ps.

Does no-one know the answer?  The other two respondents have missed the
point, as the script is a bare-bones one: in the real application, I
want the input data to be manipulated extensively by the script both
before and after calling the interactive editor.

--
mv .sig /dev/null

Quote:> The other two respondents have missed the point, as the script is a
> bare-bones one: in the real application, I want the input data to be
> manipulated extensively by the script both before and after calling
> the interactive editor.

Try closing stderr before starting vi, eg:

#!/bin/bash
SCRATCH=/tmp/scratch$$
cat > SCRATCH
exec <&2
vi SCRATCH

J?rgen

The problem is not vi-specific and affects other interactive editors.  I
used vi in the example because it gave an error message.  In reality I
use an incarnation of emacs or (ahem) ecce.

: Try closing stderr before starting vi, eg:
:
: #!/bin/bash
: SCRATCH=/tmp/scratch$$
: cat > SCRATCH
: exec <&2
: vi SCRATCH

Thanks, that works (but why?).  I tried lots of manipulations with stdin
and stdout, but not stderr.

(Of course the last two SCRATCHes in all my example scripts should have
been $SCRATCHes!)

--
mv .sig /dev/null

why don't you just learn ed?

r.

Child processes inherit open file descriptors (which explains pipes) and
stdin is still open. exec <&2 (or ''exec 0<&2'') doesn't close stderr
but links stdin with stderr. You ought to be able to solve it by linking
it to stdout as well.

J?rgen

Villy