Piping to UNIX date function -

to format date timestamp, i'd use eg date -d "2012-05-06 12:12" "+%s". if have file date per line how like:

cat file.txt | date "+%s" # not work 

i following:

cat file.txt | while read line; `date -d "$line" "+%s"`; done; 

but utterly ugly...

other solution converting date-time timestamp (in format yyyy-mm-dd hh:mm:ss) acceptable well.

edit: real life example bit more complex, let me elaborate:

`some command produces complex lines` | grep only-speicif-lines | awk '{ print $5 | (i want pass date here timestamp in end)}' 

this makes it:

while read mydate   date -d "$mydate" "+%s" done < file 

note solution

cat file.txt | while read line; `date -d "$line" "+%s"`; done; 

is not way read file line per line. need to

while read line; `date -d "$line" "+%s"`; done < file.txt                                                   ^^^^^^^^^^ 

test

$ cat 2012-05-06 12:12 2012-05-06 12:13 $ while read mydate; date -d "$mydate" "+%s"; done < 1336299120 1336299180 

---

update

from comment:

edit: real life example bit more complex, let me elaborate:

`some command produces complex lines` | grep only-speicif-lines | awk '{ print $5 | (i want pass date here 

to timestamp in end)}'

this can make it:

xargs -i date -d "{}" "+%s"  

test

$ cat | grep 2 | xargs -i date -d "{}" "+%s"  # grep here silly example 1336299120 1336299180