Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

RCS Version Functions

RCS Version Functions

Version numbers

The RCS versions numbers are 2 decimal numbers separated by a decimal point. For example iin "2.7", the major version number is 2 and the minor version number is 7. If two programs communicate there should be no problem if the versions of RCS used differ only by a minor version number, but if they differ by a major version number then it is likely that one or both programs may need to be updated.

C++ Functions

There are several ways that programmers can test the RCS version.


RCS_VERSION is a macro defined in rcs.hh, of the form "m.n", where m is the major version number and n is minor version number.


This function prints a line describing the RCS library, it's version, date compiled etc.


int rcs_version_compare(const char * compversion); 

This function allows users to determine if the RCS library linked in is newer or older than a particular version. It returns 0 if the version matches, -1 if the RCS library linked in is older than compversion, and +1 if the RCS library linked in is newer than compversion. If no minor number is included in compversion any version with the given major number will return 0.

Example 1:

main() { if(rcs_version_compare("2.5") < 0) { printf("RCS library older than 2.5\n"); } } 

Example 2:

// This example shows how to test if the rcs.hh included matches the // library that is linked in. main() { if(rcs_version_compare(RCS_VERSION) != 0) { printf("RCS library and header file don't match.\n"); } } 

Example 2:

// Only compare major number. main() { if(rcs_version_compare("2") != 0) { printf("RCS library is not version 2.\n"); } else { printf("RCS library is version 2. (It could be 2.0 or 2.99, we don't care.)\n"); }  }   

Using What to determine the Version

The SCCS what command can be used to determine the version of the library linked into an executable.
what executable_file | grep RCS_LIBRARY_VERSION  output:         RCS_LIBRARY_VERSION: 2.9 Compiled on  May  6 1997 at 15:55:35 for the  sunos5 platform.   

Java Functions

Not Implemented yet.

See Also

The list of modifications.
Created July 14, 2014, Updated January 6, 2017