Editing Guide to madagascar programs (section)

===SEG-Y specific parameters===
*<tt>hfile=</tt> specifies the name of the file in which the EBCDIC reel header will be put after conversion to ASCII. If you are certain there is no useful information in it, <tt>hfile=/dev/null</tt> works just fine. If you do not specify anything for this parameter, you will get an ASCII file named <tt>header</tt> in the current directory. If you want to quickly preview this header before running <tt>sfsegyread</tt>, use<pre>dd if=input.segy count=40 bs=80 cbs=80 conv=unblock,ascii</pre>
*<tt>bfile=</tt> specifies the name of the file in which the binary reel header (the 400-byte thing following the 3600-byte EBCDIC) will be put without any conversion. The default name is "binary". Unless you have software that knows how to read exactly this special type of file, it will be completely useless, so do <tt>bfile=/dev/null</tt>
*<tt>format=</tt> specifies the format in which the trace data samples are in the SEG-Y input file. This is read from the binary reel header of the SEG-Y file. Valid values are 1(IBM floating point), 2 (4-byte integer), 3 (2-byte integer), and 5 (IEEE floating point). If the input file is SU, the format will be assumed to be the native <tt>float</tt> format.

*<tt>keyname=</tt> specifies the byte offset to remap a header using the trace header key names shown above. For example, if the CDP locations have been placed in bytes 181-184 instead of the standard 21-24, <tt>cdp=180</tt> will remap the trace header to that location.