| % File src/library/tools/man/md5sum.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2014 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{md5sum} |
| \alias{md5sum} |
| \title{Compute MD5 Checksums} |
| \description{ |
| Compute the 32-byte MD5 hashes of one or more files. |
| } |
| \usage{ |
| md5sum(files) |
| } |
| \arguments{ |
| \item{files}{character. The paths of file(s) whose contents are to be hashed.} |
| } |
| \details{ |
| A MD5 \sQuote{hash} or \sQuote{checksum} or \sQuote{message digest} is |
| a 128-bit summary of the file contents represented by 32 hexadecimal |
| digits. Files with different MD5 sums are different: only very |
| exceptionally (and usually with the intent to deceive) are those with |
| the same sums different. |
| |
| On Windows all files are read in binary mode (as the \code{md5sum} |
| utilities there do): on other OSes the files are read in the default |
| mode (almost always text mode where there is more than one). |
| |
| MD5 sums are used as a check that \R packages have been unpacked |
| correctly and not subsequently accidentally modified. |
| } |
| \value{ |
| A character vector of the same length as \code{files}, with names |
| equal to \code{files} (possibly expanded). The elements will be |
| \code{NA} for non-existent or unreadable files, otherwise a |
| 32-character string of hexadecimal digits. |
| } |
| \source{ |
| The underlying C code was written by Ulrich Drepper and extracted from |
| a 2001 release of \code{glibc}. |
| } |
| \seealso{ |
| \code{\link{checkMD5sums}} |
| } |
| \examples{ |
| as.vector(md5sum(dir(R.home(), pattern = "^COPY", full.names = TRUE))) |
| } |
| \keyword{utilities} |
| |