Reading Call-Display

Reading Call-Display

Post by Sheldon Doy » Wed, 08 Jan 1997 04:00:00



I am interested if anyone can direct me to a FAQ or source for reading
the call display information available. Specifiacally:

- Source for Linux to read call/number display.
- Can this info be obtained from conventional data/fax modems or is
special hardware required.
- How standardized is the data acquisition(will the code work for all
Canadian/US phone systems).

Any help would be appreciated.

--
Sheldon Doyle


 
 
 

1. Bash calls TCL, TCL calls Bash, 2nd Bash never reads input

[fu-t set]

in comp.unix.misc i read:

perhaps you should resolve these deficiencies -- not that there is anything
wrong with using tcl from bash or bash from tcl, but it doesn't appear
necessary in this case.

in terms of shell scripting you don't have much debugging experience, in
particular you don't appear to have used ``set -vx'' to expose the
operations occurring.  which would lead to the real problem: you aren't
using enough quoting, which is causing ...

you have a test which expects certain arguments and they are not being
provided.  you use bare variable expansion, which does not result in an
argument being created if the variable is unset or empty.  let's look at
what that looks like using set -x.

my little test script, which is whittled down to just the problem, is:

  #!/usr/bin/bash
  set -x
  foo=''
  [ $foo == 'Y' ]

executing this provides the following output:

  + foo=
  + '[' == Y ']'
  ./foo.sh: line 4: [: ==: unary operator expected

as you can see there is no argument before the == (which is non-standard
btw), because foo is empty.  to ensure that an argument is created you need
to use quotes, i.e.,

  #!/usr/bin/bash
  set -x
  foo=''
  [ "$foo" == 'Y' ]

which after expansion becomes:

  + foo=
  + '[' '' == Y ']'

there we see that there is an empty argument being provided.

--
a signature

2. 01_v4l2-api-fix

3. Displaying system call buffers with dtrace?

4. Accelerated-X and Marimba stuff

5. Calling and display of aliases in a Kornshell script

6. remove csum_partial_copy

7. Displaying call stack

8. AIX 4.3.1 and Automounter

9. Display Call Stack

10. "can't open display" when I call xterm in crontab

11. system call/function to display free directory space

12. How to open/read a file during a function call in the networking kernel codes

13. Program hangs when calling read function