Delete specific lines of a file beginning with a certain letter

docaia · 08-24-2008, 10:24 PM

I mistakenly attached a wrong header file to a data file, the header is so long but every line of the header begins with the letter "H", every other line begins with "S".

I need a script (or a command) that allows me to delete the header lines from the files instead of deleting them manually using the vi editor.

Please i need it to be briefly explained because i may use it to fix other files with other properties.
thank you

Mr. C. · 08-24-2008, 10:28 PM

I'm confused. How can EVERY line begin with H, but also EVERY OTHER line begin with S ?

Please show a couple of sample lines.

syg00 · 08-24-2008, 10:44 PM

Semantics probably - I read it as "either".
Headers have "H", all others have "S".

Mr. C. · 08-24-2008, 10:50 PM

Ah, "every other" means "all other".

Well, then, Mr. C. said, in said case, sed is our friend:

sed '/^H/d' input.file

docaia · 08-24-2008, 11:04 PM

Every line of the "header" begins with H, the other lines begin with S, here is a small part of the file:

Quote:

H26
H26 Record Specification
H26
H26 Item Definition of Field Start Stop
H26 ---- -------------------- ----- -----
H26 1 Record Identifier 1 - 1
H26 2 (Line) 2 - 17
H26 3 (Point) 18 - 25
H26 4 (Index) 26 - 26
H26 5 Source Type (Point Code) 27 - 28
H26 6 Station Depth 33 - 36
H26 7 Easting (X) 47 - 55
H26 8 Northing (Y) 56 - 65
H26 9 Surface Elevation 66 - 71
H26 10 Acquired Date/Time(Date) 72 - 74
H26 11 Acquired Date/Time(Time) 75 - 80
H26
H26 11111111112222222222333333333344444444445555555555666666666677777777778
H26 5678901234567890123456789012345678901234567890123456789012345678901234567890
S990 49962V1 0 817875.1 205975.0 -6.9222183629
S995 49962V1 0 817877.3 206225.9 -6.0222183702
S990 49952V1 0 817825.8 205974.9 -8.6222183733
S995 49952V1 0 817826.3 206225.9 -8.6222183759
S990 49942V1 0 817775.8 205975.3 -10.0222183822
S995 49942V1 0 817775.0 206225.0 -10.2222183845
S990 49932V1 0 817725.9 205974.9 -10.8222183909
S995 49932V1 0 817726.8 206225.0 -11.2222183932