Remove text from a text file without otherwise altering the file

I need to remove text from a text file without otherwise altering the file INCLUDING other text in the same line. specifically I need the text of the form 'E\S+' (ie "E3453.464") to go away without otherwise altering the line.

so this: G1 X104.650 Y95.350 E4.58979 should become this G1 X104.650 Y95.350

and this G1 E-2.00000 F2400.00000 should become this G1 F2400.00000

Answer 1

[Paolo]

You can use regexprep for this purpose.

 x1 = 'G1 X104.650 Y95.350 E4.58979';
 x2 = 'G1 E-2.00000 F2400.00000';

 x1 = regexprep(x1,'(E-?)([0-9]){0,}\.?(\d+)\s?','');
 x2 = regexprep(x2,'(E-?)([0-9]){0,}\.?(\d+)\s?','');

 x1 = 'G1 X104.650 Y95.350 '
 x2 = 'G1 F2400.00000'

The expression:

• Match E
• Match '-' optionally
• Match numbers 0-9 at least one time
• Match '.' optionally
• Match as many digits as possible
• Match whitespace optionally

[Morpheuskibbe]

Thanks. your version doesn't actually work (I'm not sure why). but thanks for the heads up on using regexprep. I just altered the regex

regexprep(tline,'E\S+\s?','')

output snippet from your version

G92 E0
G1 X95.350 Y95.350 F360.000
G1 F2400.00000
G1 F360
M182;
G1 X104.650 Y95.350 E4.58979
G1 X104.650 Y104.650 E7.17958
G1 X95.350 Y104.650 E9.76937
G1 X95.350 Y95.425 E12.33827

output snippet from my version

G92 
G1 X95.350 Y95.350 F360.000
G1 F2400.00000
G1 F360
M182;
G1 X104.650 Y95.350 
G1 X104.650 Y104.650 
G1 X95.350 Y104.650 
G1 X95.350 Y95.425

[Paolo]

Didn't not realise E0 could occur, so I changed {1,} to {0,} However the expression I posted matches your conditions:

https://regex101.com/r/BZiZwv/1

Also in your condition you are using \S which will match anything other than a space, tab or newline, rather than matching the individuals characters as I showed. So say there is an entry as:

 Etest
 ENDING
 E?$

Your expression will remove it. Not necessarily important in this situation if you know what the information looks like however its worth noting.

[Morpheuskibbe]

It was the space between the '\s' and the '?' I think. I copy pasted the pre-edited version of yours and that spaced messed it up. It works now.

[Paolo]

No worries, glad you fixed it. I have made a very small change in the expression as I forgot to escape the '.'. Should be all good now, please find the updated code in the answer and the updated regex101 link in the comment above.

[Guillaume]

Note that {0,} is the same as * and {1,} is the same as + in regular expressions. In my opinion, E-{0,} should be E-? (aka E-{0,1})

[Paolo]

Totally, the first E-{0,} is actually meant to be E-?, as from the examples OP gave there is only one '-' character. While editing I changed both of them rather than just the second one...