How do I go to a previous line when reading a text file?

Below is the section of interest from a text file I'm trying to read.

.
.
.
3 0.68500             35.11850            -180.00000          
3 0.68500             30.97850            0.00000             
4 0.68500             99.97850            0.00000             
4 -0.18500            99.97850            -180.00000          
4 -0.18500            105.11850           0.00000             
4 0.68500             105.11850           -180.00000          
4 0.68500             99.97850            0.00000             
5 79.57000            8.96350             0.00000             
5 74.42000            8.96350             0.00000             
5 74.42000            9.83350             -180.00000          
5 79.57000            9.83350             0.00000             
5 79.57000            8.96350             -180.00000          
.END_BOARD_OUTLINE
.
.
.

The value I'm interested in is in the first column above the .END_BOARD_OUTLINE line, 5, in this case. Initially, I search through the file to find .END_BOARD_OUTLINE. I would then like to read the previous line to get the 5, but I can't find a way to move the cursor (for lack of a better term) up a line so I can read it. Is there a way to do this or do I need a different strategy to find that number?

I'm using fopen to open the file and fgetl to read the lines.

Answer 1

[Andrew Newell]

You could store the current and previous lines like this:

currline = fgetl(fid);
while ischar(currline) && ~strcmp(currline,'.END_BOARD_OUTLINE')
  prevline = currline;
  currline = fgetl(fid);
end

Then prevline contains the line you want.

EDIT: See also Reading the previous line in a text file.

[Sam G.]

Yeah, that should work. Thanks! So there's no |goto| commands or anything like that?

[Andrew Newell]

There is *fseek*, but you have to know how many bytes to go back.