| % File src/library/utils/man/compareVersion.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{compareVersion} |
| \alias{compareVersion} |
| \title{Compare Two Package Version Numbers} |
| \description{ |
| Compare two package version numbers to see which is later. |
| } |
| \usage{ |
| compareVersion(a, b) |
| } |
| \arguments{ |
| \item{a, b}{Character strings representing package version numbers.} |
| } |
| \value{ |
| \code{0} if the numbers are equal, \code{-1} if \code{b} is later |
| and \code{1} if \code{a} is later (analogous to the C function |
| \code{strcmp}). |
| } |
| \details{ |
| \R package version numbers are of the form \code{x.y-z} for integers |
| \code{x}, \code{y} and \code{z}, with components after \code{x} |
| optionally missing (in which case the version number is older than |
| those with the components present). |
| } |
| \seealso{ |
| \code{\link{package_version}}, |
| \code{\link{library}}, \code{\link{packageStatus}}. |
| } |
| \examples{ |
| compareVersion("1.0", "1.0-1") |
| compareVersion("7.2-0","7.1-12") |
| } |
| \keyword{utilities} |