^ asserts position at start of a line
From:
matches the characters From: \s matches any whitespace character (equivalent to [\r\n\t\f\v ] )
Match a single character present in the list below [ A - Za - z ]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ] )
Match a single character present in the list below [ A - Za - z ]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
1st Capturing Group ( \s [ A - Za - z ] + )?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ] )
Match a single character present in the list below [ A - Za - z ]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
2nd Capturing Group ( \s [ A - Za - z ] + )?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ] )
Match a single character present in the list below [ A - Za - z ]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ] )
< matches the character < 6010 (3C16 or 748 ) literally (case sensitive)
Match a single character present in the list below [ A - Za - z ]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
@domain
matches the characters @domain \. matches the character . 4610 (2E16 or 568 ) literally (case sensitive)
com>
matches the characters com> g modifier: g lobal. All matches (don't return after first match)
m modifier: m ulti line. Causes ^ $