It's been awhile for me too, but if I remember correctly, when regular expressions are used in text editing, regular expressions consist of zero or more characters followed by an end-of-string delimiter (typically NUL). Some utilities limit the processing to lines (0 or more characters followed by a newline character) but some utilities recognize the newline character as an ordinary character. However, I do not remember the difference between regular expressions and extended regular expressions. I think historical regular expressions are referred to basic regular expressions (BRE), but then my memory may be incorrect.



>Are you sure about that assumption? I seem to recall using regular expressions in Unix in text editing, and I'm sure that 'beginning of line' meant exactly that, and not 'beginning of text'. On the other hand, I do have to admit that by now I've pretty much forgotten just about everything I ever knew about Unix.
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>Alan
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>>>I say there are 4, and I think most normal humans would agree with me. For example, 'Regular' is at the beginning of a line.
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>>>Not according to the Regular Expressions inner workings. There is only 1 line, and it begins with 'Welcome'.
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>>Of course, the assumption is that your regular expression is in a single line, which is the way regular expressions are usually used.
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>>I believe your suggestion is more accurate, in any case.