how to edit data from a file using fgets or other comands

[adlakhadk]

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 P
ATOM 45401 O1P U B2016 78.179 -55.989-103.907 1.00 19.24 O
ATOM 45402 O2P U B2016 76.569 -57.674-104.987 1.00 19.24 O
ATOM 45403 O5* U B2016 78.427 -58.428-103.470 1.00 19.24 O
ATOM 45404 C5* U B2016 79.420 -58.250-102.460 1.00 19.24 C
ATOM 45405 C4* U B2016 80.183 -59.534-102.266 1.00 19.24 C
ATOM 45406 O4* U B2016 79.239 -60.563-101.883 1.00 19.24 O
ATOM 45407 C3* U B2016 80.883 -60.055-103.502 1.00 19.24 C
ATOM 45408 O3* U B2016 82.212 -59.535-103.483 1.00 19.24 O
ATOM 45409 C2* U B2016 80.854 -61.569-103.322 1.00 19.24 C
ATOM 45410 O2* U B2016 81.937 -62.041-102.548 1.00 19.24 O
ATOM 45411 C1* U B2016 79.551 -61.773-102.543 1.00 19.24 C
ATOM 45412 N1 U B2016 78.381 -62.149-103.349 1.00 81.32 N

the data is in tabular form and i want to append the five numeric columns on the right and keep the rest as same . someone told me to use fgets but i donot know . please suggest a detailed suitable program for the same

[niskin]

please suggest a detailed suitable program for the same

I'm afraid we can't write the program for you. You would use fgets to read the data into a variable and then, in a loop, you can write that variable into your other file.

[niskin]

It sounds like you also might want to use fseek() to be able to read the numeric columns into a variable rather than everything. Sorry I can't be of more help on this.