<quote who="david">

> Q1. why does sed lose the first line?
>
> da...@david:~/test$ cat blah
> the quick
> brown fox jumps
> over
> the lazy
> dog
> da...@david:~/test$ cat blah | while read line ; do sed s/t/T/ ; done

You want this instead:

  while read line; do echo $line | sed s/t/T/; done

I always quote my sed expressions, and use allcaps for variables. Makes it
easier to read when you're writing longer scripts. Plus you can avoid using
cat if you want:

  while read LINE; do echo $LINE | sed 's/t/T/'; done < blah

read shoves input into a variable, so you need to manipulate that variable
once your input is going there. A simpler way of expressing your original
script without the while loop:

  sed 's/t/T/' blah

;-)

> Q2. what does the @ mean?
>
> da...@david:~$ date -d @1174306440
> Mon Mar 19 23:14:00 EST 2007

It's shorthand for saying "show me the human-readable date of this
timestamp" (seconds from the epoch). You can get more info about how to use
date by reading the info page (a gnu conspiracy to confuse the fuck out of
everyone by making man pages useless in favour of some emacsed-up piece of
crap help viewer).

:-)

- Jeff

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