How to add a missing line, based on part of the previous line

guy038 · Nov 21, 2024, 11:02 AM

Hello, @dr-ramaanand and All,

@dr-ramaanand, I’ve finally managed to understand what your goal was ! Not so easy !

You said :

However, I want to know how to use a $1 after the \r\n instead of typing the whole (missing) string to be added

Well, no need to build a regex which uses Backtracking Control verbs for this task and, anyway, you’re probably not yet able to master these concepts !

So, the obvious solution is to use the following regex S/R :

SEARCH <footer(.+?class=).+?>
REPLACE $0\r\n<div$1"container">
Check the Wrap around option

Thus, from this INPUT text, pasted in a new tab :

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">

After a click on the Replace All button, you would get the expected OUTPUT text :

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="width: 100%; height: auto;" class="container">

Now, there’s still a problem with that S/R : if you repeat the Replace All action, you would wrongly get :

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="width: 100%; height: auto;" class="container">
<div style="width: 100%; height: auto;" class="container">

On the other hand, you also said :

I would also love to know how to use a ?! which is a negative look ahead, before the missing string to add it using a $1 in the Replace field

To prevent this case to occur and, as you suggested, the solution is to verify that the line <div style="width: 100%; height: auto;" class= does not exsist, right after the line <footer style="width: 100%; height: auto;" class="panel-footer footer add-top">

This leads to the final regex S/R, which uses, as you said, a negative look-ahead, containing a reference to our group 1

SEARCH <footer(.+?class=).+?>(?!\R<div\1)
REPLACE $0\r\n<div$1"container">

This time, after a first click on the Replace All button, any subsequent click on this button will display, as 'expected, the message :

Replace all: 0 occurrence were replaced in entire file

This ensures that the replacement just occurs once !

Remark :

In the search regex, you may replace the \1 syntax, within the look-ahead structure, by any of the eight following syntaxes :

\g1 , \g{1} , \g<1> , \g'1' , \k1 , \k{1} , \k<1> or \k'1'

Howewer, you CANNOT use the $1 or ${1} syntaxes in the search regex. These two syntaxes and, of course, \1, are the three syntaxes ONLY allowed in the Replace regex !

To summarize, this regex S/R adds the line <div style="width: 100%; height: auto;" class="container">, whose part space + style="width: 100%; height: auto;" class= is also a part of the previous line !

Thus, I decided to rename the title of this topic as : How to add a line, based on part of the previous line

Best Regards,

guy038

dr ramaanand · Nov 21, 2024, 2:42 PM

@guy038 merci beaucoup but, “How to add a line, based on part of the previous line if that line is missing” is a more appropriate title

dr ramaanand · Nov 21, 2024, 3:00 PM

@guy038 One of my files out of several in a folder had this footer: <footer style="top: 98.7%; width: 100%; height: auto;" class="panel-footer footer add-top"> and another had <footer style="top: 99.2%; width: 100%; height: auto;" class="panel-footer footer add-top">, so I tweaked your Regular expression to <footer style=".+?(width: 100%; height: auto;" class=).+?>(?!\R<div\1) in the Find field but then, it does not skip adding the <div style="width: 100%; height: auto;" class="container"> if it is already added in those two files. I also observe that <footer style="width: 100%; height: auto;" class="panel-footer footer add-top"> cannot be found even if there is no <div..............> on the immediate next line. Does your Regular expression need more tweaking? <footer style=".+?(width: 100%; height: auto;" class=)+?>(?!\R<div style="\1) does not find/match anything

dr ramaanand · Nov 21, 2024, 4:06 PM

I tweaked the Regular expression to <footer style="[^"]*?(width: 100%; height: auto;" class=).+?>(?!\s*<div style="\1) with $0\r\n<div style="$1"container"> in the replace field which worked and it also skipped adding the <div…> line if it was added already.

guy038 · Nov 21, 2024, 4:17 PM

Hi, @dr-ramaanand,

Sorry, but I did not understand, at all, what you want to !

If I paste in a new tab, these two lines, as INPUT :

<footer style="top: 98.7%; width: 100%; height: auto;" class="panel-footer footer add-top">

<footer style="top: 99.2%; width: 100%; height: auto;" class="panel-footer footer add-top">

my previous regex S/R :

SEARCH <footer(.+?class=).+?>(?!\R<div\1)
REPLACE $0\r\n<div$1"container">

Does return this OUTPUT text :

<footer style="top: 98.7%; width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="top: 98.7%; width: 100%; height: auto;" class="container">

<footer style="top: 99.2%; width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="top: 99.2%; width: 100%; height: auto;" class="container">

You’ll note that the added line, beginning with <div style=", is followed, as expected, with the same text that its previous line, except for the text which comes after the class attribute and which is changed as container

Do you need this behaviour ? If not, show me some examples ( before and after ) of what you need !

Now, you said :

I also observe that <footer style="width: 100%; height: auto;" class="panel-footer footer add-top"> cannot be found even if …

But, althougth the part top: ##.#%; is missing, my regex <footer(.+?class=).+?>(?!\R<div\1) does find the string

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">

Thus, from the INPUT text :

<footer style="top: 98.7%; width: 100%; height: auto;" class="panel-footer footer add-top">

<footer style="top: 99.2%; width: 100%; height: auto;" class="panel-footer footer add-top">

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">

and the regex S/R :

SEARCH <footer(.+?class=).+?>(?!\R<div\1)
REPLACE $0\r\n<div$1"container">

We get the following OUTPUT text :

<footer style="top: 98.7%; width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="top: 98.7%; width: 100%; height: auto;" class="container">

<footer style="top: 99.2%; width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="top: 99.2%; width: 100%; height: auto;" class="container">

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="width: 100%; height: auto;" class="container">

Again, if these results are NOT expected, make the effort to provide a lot of examples, which CLEARLY show what you want to !

BR

guy038

dr ramaanand · Nov 21, 2024, 4:30 PM

@guy038 said in How to add a missing line, based on part of the previous line:

<footer style=“top: 98.7%; width: 100%; height: auto;” class=“panel-footer footer add-top”>

<footer style=“top: 99.2%; width: 100%; height: auto;” class=“panel-footer footer add-top”>

<footer style=“width: 100%; height: auto;” class=“panel-footer footer add-top”>

If the above is the input text, with your RegEx, the output is exactly as you showed above but I want the output in all three cases to be <div style="width: 100%; height: auto;" class="container">

dr ramaanand · Nov 21, 2024, 4:37 PM

@guy038 …so I tweaked the Regular expression to be used in the Find field to <footer style="[^"]*?(width: 100%; height: auto;" class=).+?>(?!\s*<div style="\1) with $0\r\n<div style="$1"container"> in the replace field which added the <div.........> line and it also skipped adding the <div,…> line if it was added already.

dr ramaanand · Nov 21, 2024, 4:51 PM

@guy038 The very first solution I had provided, right on top was actually perfect but I thought the <div.............> string could be captured in a group. However, someone at regex101.com explained that SKIP is just an optimization to say, “don’t just move 1 character and try again”, it says, “move ALL these characters and try again”, so if something is skipped with a (*FAIL) or (*F), we can’t capture it in a group

guy038 · Nov 21, 2024, 5:14 PM

Hello, @dr-ramaanand and All,

Ah…, I’ve just tested your S/R and it works nicely !

Now, you can even simplify your S/R to this version :

SEARCH <footer.+?(width.+?class=).+?>(?!\R<div style="\1)
REPLACE $0\r\n<div style="$1"container">

Now, if, in your very first post, you had said :

From this INPUT text :

<footer style="top: 98.7%; width: 100%; height: auto;" class="panel-footer footer add-top">

<footer style="top: 99.2%; width: 100%; height: auto;" class="panel-footer footer add-top">

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">

I would like this OUTPUT text :

<footer style="top: 98.7%; width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="width: 100%; height: auto;" class="container">

<footer style="top: 99.2%; width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="width: 100%; height: auto;" class="container">

<footer style="width: 100%; height: auto;" class="panel-footer footer add-top">
<div style="width: 100%; height: auto;" class="container">

Everything would have been much more simple, you know !?

Best Regards,

guy038

dr ramaanand · Nov 21, 2024, 5:37 PM

@guy038 Oui, merci beaucoup!