4. Logfile Structure

The logfile is a text file easy to read and edit. It is formed of two parts, the status line and the list of data blocks.

NOTE: Logfiles generated by a version of ddrescue prior to 1.6 lack the status line. If you want to use an old logfile with ddrescue 1.6 or later, you will have to insert a line like ‘0 +’ at the beginning of the logfile.

The first non-comment line is the status line. It contains a non-negative integer and a status character. The integer is the position being tried in the input file. The status character is one of these:

Every line in the list of data blocks describes a block of data, and contains 2 non-negative integers and a status character. The first integer is a position in the input file, the second is the size (in bytes) of the data to be copied. The status character is one of these:

And here is an example logfile:

# Rescue Logfile. Created by GNU ddrescue version 1.10
# current_pos current_status
0x00120000 ?
# pos size status

Any line beginning with ‘#’ is a comment line. The blocks must be contiguous and non-overlapping.

If you edit the file, you may use decimal, hexadecimal or octal values, using the same syntax that integer constants in C++.