[Chicago-talk] removing line from file.
Andy_Bach at wiwb.uscourts.gov
Andy_Bach at wiwb.uscourts.gov
Wed Mar 9 12:42:37 PST 2005
Larry thought of everything ...
perldoc perlop
...
Binary ".." is the range operator, which is really two different
operators depending on the context.
...
In scalar context, ".." returns a boolean value. The
operator is bistable, like a flip-flop, and emulates the
line-range (comma) operator of awk, and various
editors. Each ".." operator maintains its own boolean
state. It is false as long as its left operand is false.
Once the left operand is true, the range operator stays true
until the right operand is true, AFTER which the range
operator becomes false again. It doesn't become false till
the next time the range operator is evaluated. It can test
the right operand and become false on the same evaluation it
became true (as in awk), but it still returns true once. If
you don't want it to test the right operand till the next
evaluation, as in sed, just use three dots
("...") instead
of two. In all other regards, "..." behaves just like ".."
does.
...
If either operand of scalar ".." is a
constant expression, that operand is implicitly compared to
the $. variable, the current line number.
a
Andy Bach, Sys. Mangler
Internet: andy_bach at wiwb.uscourts.gov
VOICE: (608) 261-5738 FAX 264-5932
In 1968 it took the computing-Power of 2 C-64 to fly a rocket to the moon.
Now, 1997 it takes the Power of a Pentium 133 to run Microsoft Windows 95.
Something must have gone wrong.
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