Regular Expressions

[Keith McLeod]

Any recommendations for good regular Expression books?  I am finding that many interfaces have a significant call for the use of regular expressions.

Or better yet any tools for this?

Latest request to find ‘(NOTE:)10/27/06)’ and put a ~ right after this.  Somtimes the date is there and sometimes not.

Also have mutli lab results with different formats with no line break characters.  Some are identified by 3 spaces, some have 12 spaces as the beginning of the new lines.  SO I would like to find exactly 12 spaces and replace with ~ and 12 spaces.  On e the smaller side I would like to find exactly 3 spaces and replace with ~ and 3 spaces…..I think Regular expressions could help in getting these formats more correct.  Thanks…

Topic

[Max Drown (Infor)]

Practical Programming in  Tcl and Tk by Welch/Hobbs

Mastering Regular Expressions by Jeffrey E.F. Friedl (O’Reilly)

Google by Goole 🙂

-- Max Drown (Infor)

[Max Drown (Infor)]

Code:

set line “(NOTE:)10/27/06”
#set line “(NOTE:)”
regsub {((NOTE:).*$)} $line {1~} line
puts $line

-- Max Drown (Infor)

[Max Drown (Infor)]

Code:

set line ”            ”
regsub {( {12})} $line {~1} line
puts $line

Code:

set line ”   ”
regsub {( {3})} $line {~1} line
puts $line

These are just simple examples, but you should probably add some anchors if possible (like ^ and $) to help eliminate invalid matches.

-- Max Drown (Infor)

[Jamin Gray]

Code:

regsub {(NOTE:)(d{2}/d{2}/d{2})?)} $x {~} x

where $x is your string.  This one is a bit more specific about the pattern, looking for the optional date instead of just any text.  And it illustrates the escape in the replacement which evaluates to all of the match.

[Max Drown (Infor)]

… or to cover cases where only one digit is used for month or day and 2 or 4 digits for year …

Code:

regsub {(NOTE:)(d{1,2}/d{1,2}/d{2,4})?)} $x {~} x

-- Max Drown (Infor)

[Steve Carter]

Regular Expression Pocket Reference by O’Reilly is also a handy one to have around.

[Author]

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