UNIX for Dummies Questions & Answers

Hi

Can anyone explain me in detail the following instructions (1st and 2nd line only)?

ls | \
while IFS= read filename
do
(some other instructions)
done

Thanks in advance.
Lazy

The code:

Code:

ls |

is sending the output of the ls command onto the next command's input (stdin) rather than to the display.
The:

Code:

\

causes the shell to treat the following line as it it was on the same line, e.g.:

Code:

ls | \
more

is the same as:

Code:

ls | more

The line:

Code:

while IFS= read filename

causes each filename from the ls command to be used to set the variable ${filename} which can then be used in the code between the "do" and "done". The "IFS=" sets the separator character that is used to differentiate between one filename and the next.
If the separator is taken to be a space then the following would do the same but by replacing spaces with commas and then using a comma as the separator:

Code:

$ ls | sed -e 's/ /,/g' | while IFS="," read filename; do echo FILENAME = $filename; done

Thanks Tony - you gave me a very understandable reply. Regards - Lazy