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Sometimes simple escaping is not possible with the characters you've listed. For example, using a backslash to escape a bracket isn't going to work in the left hand side of a substitution string in sed, namely

sed -e 's/foo\(bar/something_else/' 

I tend to just use a simple character class definition instead, so the above expression becomes

sed -e 's/foo[(]bar/something_else/' 

which I find works for most regexp implementations.

BTW Character classes are pretty vanilla regexp components so they tend to work in most situations where you need escaped characters in regexps.

Edit: After the comment below, just thought I'd mention the fact that you also have to consider the difference between finite state automata and non-finite state automata when looking at the behaviour of regexp evaluation.

You might like to look at "the shiny ball book" aka Effective Perl (sanitised Amazon link), specifically the chapter on regular expressions, to get a feel for then difference in regexp engine evaluation types.

Not all the world's a PCRE!

Anyway, regexp's are so clunky compared to SNOBOL! Now that was an interesting programming course! Along with the one on Simula.

Ah the joys of studying at UNSW in the late '70's! (-:

HTH

cheers,

Rob

Sometimes simple escaping is not possible with the characters you've listed. For example, using a backslash to escape a bracket isn't going to work in the left hand side of a substitution string in sed, namely

sed -e 's/foo\(bar/something_else/' 

I tend to just use a simple character class definition instead, so the above expression becomes

sed -e 's/foo[(]bar/something_else/' 

which I find works for most regexp implementations.

BTW Character classes are pretty vanilla regexp components so they tend to work in most situations where you need escaped characters in regexps.

Edit: After the comment below, just thought I'd mention the fact that you also have to consider the difference between finite state automata and non-finite state automata when looking at the behaviour of regexp evaluation.

You might like to look at "the shiny ball book" aka Effective Perl (sanitised Amazon link), specifically the chapter on regular expressions, to get a feel for then difference in regexp engine evaluation types.

Not all the world's a PCRE!

Anyway, regexp's are so clunky compared to SNOBOL! Now that was an interesting programming course! Along with the one on Simula.

Ah the joys of studying at UNSW in the late '70's! (-:

Sometimes simple escaping is not possible with the characters you've listed. For example, using a backslash to escape a bracket isn't going to work in the left hand side of a substitution string in sed, namely

sed -e 's/foo\(bar/something_else/' 

I tend to just use a simple character class definition instead, so the above expression becomes

sed -e 's/foo[(]bar/something_else/' 

which I find works for most regexp implementations.

BTW Character classes are pretty vanilla regexp components so they tend to work in most situations where you need escaped characters in regexps.

Edit: After the comment below, just thought I'd mention the fact that you also have to consider the difference between finite state automata and non-finite state automata when looking at the behaviour of regexp evaluation.

You might like to look at "the shiny ball book" aka Effective Perl (sanitised Amazon link), specifically the chapter on regular expressions, to get a feel for then difference in regexp engine evaluation types.

Not all the world's a PCRE!

HTH

cheers,

Rob

HTH

cheers,

Rob

Sometimes simple escaping is not possible with the characters you've listed. For example, using a backslash to escape a bracket isn't going to work in the left hand side of a substitution string in sed, namely

sed -e 's/foo\(bar/something_else/' 

I tend to just use a simple character class definition instead, so the above expression becomes

sed -e 's/foo[(]bar/something_else/' 

which I find works for most regexp implementations.

BTW Character classes are pretty vanilla regexp components so they tend to work in most situations where you need escaped characters in regexps.

Edit: After the comment below, just thought I'd mention the fact that you also have to consider the difference between finite state automata and non-finite state automata when looking at the behaviour of regexp evaluation.

You might like to look at "the shiny ball book" aka Effective Perl (sanitised Amazon link), specifically the chapter on regular expressions, to get a feel for then difference in regexp engine evaluation types.

Not all the world's a PCRE!

Anyway, regexp's are so clunky compared to SNOBOL! Now that was an interesting programming course! Along with the one on Simula.

Ah the joys of studying at UNSW in the late '70's! (-:

HTH

cheers,

Rob

Sometimes simple escaping is not possible with the characters you've listed. For example, using a backslash to escape a bracket isn't going to work in the left hand side of a substitution string in sed, namely

sed -e 's/foo\(bar/something_else/' 

I tend to just use a simple character class definition instead, so the above expression becomes

sed -e 's/foo[(]bar/something_else/' 

which I find works for most regexp implementations.

BTW Character classes are pretty vanilla regexp components so they tend to work in most situations where you need escaped characters in regexps.

HTH

cheers,

Rob

Sometimes simple escaping is not possible with the characters you've listed. For example, using a backslash to escape a bracket isn't going to work in the left hand side of a substitution string in sed, namely

sed -e 's/foo\(bar/something_else/' 

I tend to just use a simple character class definition instead, so the above expression becomes

sed -e 's/foo[(]bar/something_else/' 

which I find works for most regexp implementations.

BTW Character classes are pretty vanilla regexp components so they tend to work in most situations where you need escaped characters in regexps.

Edit: After the comment below, just thought I'd mention the fact that you also have to consider the difference between finite state automata and non-finite state automata when looking at the behaviour of regexp evaluation.

You might like to look at "the shiny ball book" aka Effective Perl (sanitised Amazon link), specifically the chapter on regular expressions, to get a feel for then difference in regexp engine evaluation types.

Not all the world's a PCRE!

HTH

cheers,

Rob

HTH

cheers,

Rob