Shell Programming and Scripting

Hi ,
I need your help to know the exact operation of this following code ..

cat file1 | ux2dos | tr -d ''>>file2

file1 contains only one line : "DTS-PO\SPECTRUM WO 56"
the data contains a META CHAR "\" .. look at the above line.
But , The file2 output contains : "DTS-POSPECTRUM WO 56^M"
The "\" does not appear in the file2.
The ux2dos appends ^M in the end of line.

My questions are :

1. what is the operation performed by tr -d '' ?
what is the usage of this arrow mark option ?
2. is the arrow option ignore the ALL Special meta char's? or the ux2dos ignore or delete the special META Char's?
3. is there any way to allow the meta char's would be appeared in the file2?

Note : Environment = IBM AIX 5.3
Shell = ksh

tr -d " does not make any sense.

Are you sure it was not tr -d "\""?

fpmurphy: his example has a literal control character which my browser displays as an empty box.

This smells of homework from the intro course. @vparunkumar: Read the book your lecturer gave you, it has the answers and that's why he gave it to you.

Send him o her our regards, you can say we awarded a "Useless Use of Cat Award" for this example.

Agreed with era..

But to get you going , following is the one of the most common usgaes of tr -d..

Code:

ls -l /home/nua7 | tr -d " " | cut -d " " -f2

This would list all files in the given path, equally space out the fields with a space " ", which is further used as a demiliter in cut command.

Hope this helps..!

In my previous post , some char was missing in tr command !!!

the actual script line looks like

cat file1 | ux2dos | tr -d '->' >>file2

i could not able to copy/paste the exact symbol.. this editor doesnt accept ... , but it is a perfect arrow symbol(->)

To era : :-)
This is not LAB exercise .....real time issue ...
I am working in IBM India..and i am new to AIX/UNIX . This is a bug , which i found .. But i could not understand the meaning of arrow symbol ..
could you help me ?

tr -d removes any occurrence of the indicated character(s) from the input, and copies the rest. A very quick glance at the tr(1) manual page would have told you this.

Conventionally ux2dos replaces line feeds with carriage return+line feed but it's not a standard command, it could do other stuff like change slashes in file names to backslashes or what not if it's a specialized command. (Often unix2dos is a simple wrapper around a one-line tr or sed script, too.)

If you don't want to remove the mystery arrow character, take out the "tr". I assume it was put there for a reason, though.

Sorry for the sarcasm, and hope this helps.

I am a fresh engineering graduate , recently joined in IBM .. and new to this AIX/unix
Thanks for your valuable reply ..

Now i understood the tr -d command ..

is the problem due to ux2dos conversion ?
will ux2dos change/modify the input string which contains meta char ?

please give me some links , to read about ux2dos ?