I want to edit a PDB file (Protein Data Bank ) using C programming language and I am using a linux platform. I donot know much about the language but want to append some columns in another file keeping the rest same .I have developed the portion on editing the Specific columns but I donot know the file structure and related programming , my data looks like

ATOM 45400 P U B2016 77.414 -57.257-103.840 1.00 19.24 ...