The C formatted I/O commands are not exactly an industry standard but they're close to it. For instance, MATLAB's are very similar and even have misleadingly similar names. So learning this stuff is a good investment. This directory has files: README: this file data (this name is compiled into iotest.c). Data is a text line (see below). iotest.c exercises some formatted reading and writing makefile makes an executable called test from iotest.c. I made the data file in an editor -- it is of the form My is months and days old. In fact right now it is My niece is 8 months and 3.3333 days old. but you can write your own. To compile and run: make ./test On your system maybe you can just say test but mine's set up to need the "in this directory" prefix of ./ test creates a file of the same name as in the data file: you can list it with the 'less' or 'more' or 'cat' commands to check that the program does the right thing, and of course the code prints it out as well. gcc creates a compiled iotest.o file for linking into your executable test. The makefile has an option to remove all these pesky .o files with make clean The scanf and printf formatters are very powerful and have lots of features. In fact you'll see I discovered one while doing this little exercise today. My reference was Programming in ANSI C by Stephen G. Kochan but I'm sure there are adequate references and tutorials on the web to duplicate this particular print version. 173 does NOT require all that complication and power: The features shown in this little example should suffice. Given the basic idea behind formatted reading and writing, about all you need to remember or look up are the codes for 'int' 'string' 'float', etc. Of course there are ways to specify the number of digits before and after the decimal point, etc. etc.