what does one # stand for?
what does two ## stand for?
what does % mean?
what does two signs %% mean?
what 1* means here?
what *1 means here?
I searched google but I got hard explanation and hard english.
I need someone to explain each command to me in easy words!
thanks.
${X} is a variable in its full syntax
Quote:
what does one # stand for?
Mask a regular expression, taking the less greedy portion, starting from left to right.
e.i.
Match as less as possible, zero or more characters, followed by a literal '1'
In your case if x="a1 b1 c2 d2" it matches 'a','1' and stops, returning the remainder as the result. "b1 c2 d2"
Quote:
what does two ## stand for?
Mask a regular expression taking the most greedy portion starting from left to right e.i
${x##*1} -> match as much as it can. Returns remainder.
if x="a1 b1 c2 d2" then it eats 'a','1',' ','b','1' and stops.
Quote:
what does % mean?
Start from right to left matching as less as possible.
Quote:
what does two signs %% mean?
Start from right to left matching as much as possible
Quote:
what 1* means here?
Match a literal '1' followed by zero or more characters. (translates to nothing or everything else after a '1' included)
Quote:
what *1 means here?
Match zero or more characters followed by a literal '1'. (Translates to everything before a literal '1' or nothing plus '1')
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