Bash, awk and file descriptors

Question

Hi guys,
I'm thinking about this piece of command lines:
[user@host ~]$ echo "first word" > test
[user@host ~]$ cat test
first word
[user@host ~]$ { rm ./test && awk -F' ' '{ print $2,$1 }' > ./test; } < ./test
[user@host ~]$ cat test
word first
[user@host ~]$ { awk -F' ' '{ print $2,$1 }' > ./test; } < ./test
[user@host ~]$ cat test
[user@host ~]$ ls -l test
-rw-r--r-- 1 user user 0 17 apr 22.06 test
I wonder why:
{ rm ./test && awk -F' ' '{ print $2,$1 }' > ./test; } < ./test
works as I expect (the file "test" have words in reverse order), while instead:
{ awk -F' ' '{ print $2,$1 }' > ./test; } < ./test
give a file "test" empty, with size 0.
Why and how the leding "rm" make the difference?
Thanks

Answer 1

Mine wrote:
bohoomil wrote:OP
AHAHAH... you're very amusing.
Op has many meanings, what of the thoundas I find on internet is the meaning /dev/zero was thinking?
OP=OPerating system
OP=Original Poster
OP=Operator Access
(and so on...)
Less sarcasm (offsite) and more pragmatism, please.
http://netforbeginners.about.com/od/int … -Is-OP.htm
Happy ?