From your post, I tried to find a generic way to achieve this kind of question, with regexes ! Please, just consider my solution as, only, one, among all the possible solutions !

The Fabrizio’s goal is to perform a Search/Replacement on a line, ONLY IF a SPECIFIC condition is true on that particular line

I would use the general regex syntax, below :

(Regex_Condition)[^@\r\n]*$|(Search_Regex)(?=.*@)|@

(?1$0@)(?2Replacement_Regex)

IMPORTANT :

• Go back to the very beginning of your current file

• In the Replace dialog, check the Regular search mode

• Check, preferably, the Match case option

• Click TWICE on the Replace All button

NOTES :

• The arobase character @, is, simply, any single character, which DOES NOT exist in your current file. and preferably, NOT a meta-character of regular expressions. So, according to your file’s contents, you can choose, for instance, the ! character, the # character, the % character, the & character, the = character, the _ character, …

• Regex_Condition represents the regex that satisfies the specific condition, which allows the associated Search/Replacement. Of course, Regex_Condition may be, also, a simple literal string, even a single character !

• Search_Regex represents, of course, the area of text, which will be replaced. As above, Search_Regex may be, only, a simple literal string, even a single character !

• Replacement_Regex is, obviously, the regex to generate the text that will replace the area matched by the Search_Regex

Below, I’ll expose 3 different examples ( The Fabrizio’s one and two others )

Regex_Condition :   ^Value=                     Search_Regex :   \bbla\b               Replacement_Regex :   blue 

Regex_Condition :   \b\d\d-\d\d-\d\d\b          Search_Regex :   [a-z]                 Replacement_Regex :   \u\2 

Regex_Condition :   \d$                         Search_Regex :   [[:alpha:]]+          Replacement_Regex :   <\2> 

• In the first case, we’ll replace the lowercase word bla, with the word blue, ONLY on lines beginning with the exact string Value=
  ( Fabrizio’s problem )

• In the second case, we’ll replace any lowercase letter, with the same uppercase letter, ONLY on lines that contain a date, of the general form xx-xx-xx, at any position of the line

• In the third case, we’ll replace any set of uppercase or lowercase letters, with the same set, surrounded by the two angle brackets, ONLY, if the current line ends with a digit

To see the results of each example, I’ll use the SAME 10 lines test example, below :

Value= bla bla testblatest bla
That's only "bla bla" speech
My NEXT bithday falls on 19-05-16
Every 25-12, Chistmas is celebrated
Value= Test of bla and BLA
Christmas is celebrated each 25-12
On the 01-01-17, we'll wish a Good New Year
Don't change the word "bla", in that TEST line no 8
01-01-00 was the first day OF THAT century
Value=     bla blabla bla

So the first example :

(^Value=)[^@\r\n]*$|(\bbla\b)(?=.*@)|@

(?1$0@)(?2blue)

would give the changed text ( Lines 1, 5 and 10 ), below :

Value= blue blue testblatest blue
That's only "bla bla" speech
My NEXT bithday falls on 19-05-16
Every 25-12, Chistmas is celebrated
Value= Test of blue and BLA
Christmas is celebrated each 25-12
On the 01-01-17, we'll wish a Good New Year
Don't change the word "bla", in that TEST line no 8
01-01-00 was the first day OF THAT century
Value=     blue blabla blue

The second example :

(\b\d\d-\d\d-\d\d\b)[^@\r\n]*$|([a-z])(?=.*@)|@

(?1$0@)(?2\u\2)

would give the changed text ( Lines 3, 7 and 9 ), below :

Value= bla bla testblatest bla
That's only "bla bla" speech
MY NEXT BITHDAY FALLS ON 19-05-16
Every 25-12, Chistmas is celebrated
Value= Test of bla and BLA
Christmas is celebrated each 25-12
ON THE 01-01-17, WE'LL WISH A GOOD NEW YEAR
Don't change the word "bla", in that TEST line no 8
01-01-00 WAS THE FIRST DAY OF THAT CENTURY
Value=     bla blabla bla

Finally, the third example :

(\d$)[^@\r\n]*$|([[:alpha:]]+)(?=.*@)|@

(?1$0@)(?2<\2>)

would give the changed text ( Lines 3, 6 and 8 ), below :

Value= bla bla testblatest bla
That's only "bla bla" speech
<My> <NEXT> <bithday> <falls> <on> 19-05-16
Every 25-12, Chistmas is celebrated
Value= Test of bla and BLA
<Christmas> <is> <celebrated> <each> 25-12
On the 01-01-17, we'll wish a Good New Year
<Don>'<t> <change> <the> <word> "<bla>", <in> <that> <TEST> <line> <no> 8
01-01-00 was the first day OF THAT century
Value=     bla blabla bla

NOTES :

• Throughout these 3 examples, the lines 2 and 4, which do not begin with the string Value= nor end with a digit and which do not contain any date, remain UNCHANGED

• For a correct behaviour of the proposed regexes, don’t forget to click, TWICE, on the Replace All button

Best Regards,

guy038

P.S. :

The underlined idea, about these general regexes, below :

(Regex_Condition)[^@\r\n]*$|(Search_Regex)(?=.*@)|@

(?1$0@)(?2Replacement_Regex)

is :

• Add a specific character ( @, or else, not used in current file ) at the end of EACH line that satisfies the Regex_Condition ( 1st S/R )

• Perform the wanted S/R, ONLY on the lines that end with the @ character ( or else ) and finally delete that extra character, at the end of each concerned line ( 2nd S/R )

As usual, I could give some extra information about these regexes, if needed !

sounds like a regex topic but solution depends on how line exactly looks.
E.g. from regex point of view it is different if line is value=bla or value = bla.
So without knowing how the lines are exactly we can only provide a roughly answer like mark regular expression in search mode and search for
(value=)bla bla and replace with \1blue.

Cheers
Claudia

in the search box
\nvalue=

and select radio button

extended \n,\r

worked for me - this was a DEC EVE feature great to see it in here

Oh just read your post properly - guess that’s not what you want.

On Unix you could use grep etc

and select radio button

extended \n,\r

worked for me - this was a DEC EVE feature great to see it in here