START-INFO-DIR-ENTRY
* Text utilities: (textutils). GNU text utilities.
* cat: (textutils)cat invocation. Concatenate and write files.
-* tac: (textutils)tac invocation. Reverse files.
-* nl: (textutils)nl invocation. Number lines and write files.
-* od: (textutils)od invocation. Dump files in octal, etc.
+* cksum: (textutils)cksum invocation. Print POSIX CRC checksum.
+* comm: (textutils)comm invocation. Compare sorted files by line.
+* csplit: (textutils)csplit invocation. Split by context.
+* cut: (textutils)cut invocation. Print selected parts of lines.
+* expand: (textutils)expand invocation. Convert tabs to spaces.
* fmt: (textutils)fmt invocation. Reformat paragraph text.
-* pr: (textutils)pr invocation. Paginate or columnate files.
* fold: (textutils)fold invocation. Wrap long input lines.
* head: (textutils)head invocation. Output the first part of files.
-* tail: (textutils)tail invocation. Output the last part of files.
+* join: (textutils)join invocation. Join lines on a common field.
+* md5sum: (textutils)md5sum invocation. Print or check message-digests.
+* nl: (textutils)nl invocation. Number lines and write files.
+* od: (textutils)od invocation. Dump files in octal, etc.
+* paste: (textutils)paste invocation. Merge lines of files.
+* pr: (textutils)pr invocation. Paginate or columnate files.
+* sort: (textutils)sort invocation. Sort text files.
* split: (textutils)split invocation. Split into fixed-size pieces.
-* csplit: (textutils)csplit invocation. Split by context.
-* wc: (textutils)wc invocation. Byte, word, and line counts.
* sum: (textutils)sum invocation. Print traditional checksum.
-* cksum: (textutils)cksum invocation. Print POSIX CRC checksum.
-* md5sum: (textutils)md5sum invocation. Print RFC1321 MD5 digest.
-* sort: (textutils)sort invocation. Sort text files.
-* uniq: (textutils)uniq invocation. Uniqify files.
-* comm: (textutils)comm invocation. Compare sorted files by line.
-* cut: (textutils)cut invocation. Print selected parts of lines.
-* paste: (textutils)paste invocation. Merge lines of files.
-* join: (textutils)join invocation. Join lines on a common field.
+* tac: (textutils)tac invocation. Reverse files.
+* tail: (textutils)tail invocation. Output the last part of files.
* tr: (textutils)tr invocation. Translate characters.
-* expand: (textutils)expand invocation. Convert tabs to spaces.
* unexpand: (textutils)unexpand invocation. Convert spaces to tabs.
+* uniq: (textutils)uniq invocation. Uniqify files.
+* wc: (textutils)wc invocation. Byte, word, and line counts.
END-INFO-DIR-ENTRY
@end format
@end ifinfo
@ifinfo
This file documents the GNU text utilities.
-Copyright (C) 1994 Free Software Foundation, Inc.
+Copyright (C) 1994, 95 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@page
@vskip 0pt plus 1filll
-Copyright @copyright{} 1994 Free Software Foundation, Inc.
+Copyright @copyright{} 1994, 95 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
utilities.
@menu
-* Introduction:: Caveats, overview, and authors.
-* Common options:: Common options.
-* Output of entire files:: cat tac nl od
-* Formatting file contents:: fmt pr fold
-* Output of parts of files:: head tail split csplit
-* Summarizing files:: wc sum cksum md5sum
-* Operating on sorted files:: sort uniq comm
+* Introduction:: Caveats, overview, and authors.
+* Common options:: Common options.
+* Output of entire files:: cat tac nl od
+* Formatting file contents:: fmt pr fold
+* Output of parts of files:: head tail split csplit
+* Summarizing files:: wc sum cksum md5sum
+* Operating on sorted files:: sort uniq comm
* Operating on fields within a line:: cut paste join
-* Operating on characters:: tr expand unexpand
-* Opening the software toolbox:: The software tools philosophy.
-* Index:: General index.
+* Operating on characters:: tr expand unexpand
+* Opening the software toolbox:: The software tools philosophy.
+* Index:: General index.
@end menu
@end ifinfo
@end example
@dfn{Records} are separated by instances of a string (newline by
-default)). By default, this separator string is attached to the end of
+default). By default, this separator string is attached to the end of
the record that it follows in the file.
The program accepts the following options. Also see @ref{Common options}.
@end example
@code{fmt} reads from the specified @var{file} arguments (or standard
-input if none), and writes to standard output.
+input if none are given), and writes to standard output.
By default, blank lines, spaces between words, and indentation are
preserved in the output; successive input lines with different
The output files' names consist of a prefix (@samp{xx} by default)
followed by a suffix. By default, the suffix is an ascending sequence
of two-digit decimal numbers from @samp{00} and up to @samp{99}. In any
-case, concatenating the output files in sorted order by file name
+case, concatenating the output files in sorted order by filename
produces the original input file.
By default, if @code{csplit} encounters an error or receives a hangup,
* wc invocation:: Print byte, word, and line counts.
* sum invocation:: Print checksum and block counts.
* cksum invocation:: Print CRC checksum and byte counts.
-* md5sum invocation:: Print RFC1321 MD5 message digest.
+* md5sum invocation:: Print or check message-digests.
@end menu
@pindex cksum
@cindex cyclic redundancy check
+@cindex CRC checksum
@code{cksum} computes a cyclic redundancy check (CRC) checksum for each
given @var{file}, or standard input if none are given or for a
@var{file} of @samp{-}. Synopsis:
-Synopsis:
-
@example
cksum [@var{option}]@dots{} [@var{file}]@dots{}
@end example
-@code{cksum} prints the CRC for each file along with the number of bytes
-in the file, and the file name unless no arguments were given.
+@code{cksum} prints the CRC checksum for each file along with the number
+of bytes in the file, and the filename unless no arguments were given.
@code{cksum} is typically used to ensure that files have been
transferred by unreliable means (e.g., netnews) have not been corrupted,
by comparing the @code{cksum} output for the received files with the
-@code{cksum} output for the original files (usually given in the
+@code{cksum} output for the original files (typically given in the
distribution).
The CRC algorithm is specified by the POSIX.2 standard. It is not
-compatible with the BSD or System V @code{sum} programs; it is more
-robust.
+compatible with the BSD or System V @code{sum} algorithms (see the
+previous section); it is more robust.
+
+The only options are @samp{--help} and @samp{--version}. @xref{Common
+options}.
@node md5sum invocation
-@section @code{md5sum}: Print RFC1321 MD5 message digest.
+@section @code{md5sum}: Print or check message-digests
@pindex md5sum
-@cindex MD5
-@cindex message digest
-@cindex fingerprint
-@cindex RFC1321
-
-@noindent
-RFC1321 says about the message digest produced by @code{md5sum}
-
-@quotation
-it is conjectured that it is computationally infeasible to produce two
-messages having the same message digest, or to produce any message
-having a given prespecified target message digest.
-@end quotation
-
-Therefor the message digest produced by @code{md5sum} is a much more
-reliable test for a change in a file.
-
-By default @code{md5sum} computes for each @var{file} the message digest
-and prints it. If the file name is @samp{-} standard input is read.
-When signaled @code{md5sum} also can compare the values in an exiting
-message digest catalog with newly computed values, telling about
-differences.
+@cindex 128-bit checksum
+@cindex checksum, 128-bit
+@cindex fingerprint, 128-bit
+@cindex message-digest, 128-bit
-Synopsis:
+@code{md5sum} computes a 128-bit checksum (or @dfn{fingerprint} or
+@dfn{message-digest} for each given @var{file}, or standard input if
+none are given or for a @var{file} of @samp{-}. It can also check if the
+checksum has changed. Synopsis:
@example
md5sum [@var{option}]@dots{} [@var{file}]@dots{}
@end example
-When computing message digests @code{md5sum} writes for each input file in
-line with the message digest, a binary/text flag, and the file name. The
-binary/text flag is nt important on UN*X systems. But ``strange''
-systems (as MSDOG) have different representations for text files in
-memory and on the disk. To get the same results for these files on an
-UN*X machine the text is converted on the fly while reading.
-
-If checking against an existing message digest catalog is requested
-the catalog file should be the output of a former run of @code{md5sum}.
-Any lines not in the correct format will be ignored. If all three
-fields are correctly read the message digest for the specified file will
-be computed in compared with the digest given in the catalog file. Any
-differences will be signaled.
+For each @var{file}, @samp{md5sum} outputs the MD5 checksum, a flag
+indicating a binary or text input file, and the filename.
+The program accepts the following options. Also see @ref{Common options}.
@table @samp
@itemx --binary
@opindex -b
@opindex --binary
-Treat all files as binary files. I.e. even on systems which make
-differences between the text and binary file representation the files
-are read just as they are store on the disk. The is the default value.
-To toggle the behaviour use the @samp{--text} option.
+@cindex binary input files
+Treat input files as binary. This makes no difference on Unix systems,
+but other systems have different internal and external character
+representations, notably to mark end-of-line.
-@item -c @var{file}
+@item -c
@itemx --check=@var{file}
-@opindex -c
-@opindex --check
-Check for the files given in @var{file} whether the message digest is
-different to the one given in @var{file}. The format of file is
+@var{file} is taken as the output of a former run of @samp{md5sum}: each
+line consists of an MD5 checksum, a binary/text flag, and a filename.
+The file will be opened (with each possible relative path) and the its
+message-digest computed. If this computed message digest is not the
+same as that given in the line, the file will be marked as failed.
-@example
-<32 character hexadecimal message digest> <binary flag> <filename>
-@end example
-
-
-@item -s[@var{string}]
-@itemx --string=[@var{string}]
+@item -s
+@itemx --string=@var{string}
@opindex -s
@opindex --string
-Instead of computing the messages digest for a file do it for the given
-@var{string}. Note that the string is an @emph{optional} argument.
+Compute the message digest for @var{string}, instead of for a file. The
+result is the same as for a file with contains exactly @var{string}.
@item -t
@itemx --text
@opindex -t
-@opindex --test
-Treat all input files as text files. As explained above this makes it
-possible to get the same message digest for a text file on all systems.
-
+@opindex --text
+@cindex text input files
+Treat all input files as text files. This is the reverse of
+@samp{--binary}.
@item -v
@itemx --verbose
@opindex -v
@opindex --verbose
-Print more information while processing.
-
+Print progress information.
@end table
* Putting the tools together::
@end menu
+
@node Toolbox introduction
@unnumberedsec Toolbox introduction
55555
@end example
-A single dash as a file name tells @code{comm} to read standard input
+The single dash as a filename tells @code{comm} to read standard input
instead of a regular file.
Now we're ready to build a fancy pipeline. The first application is a word
projects / thirdparty / coreutils.git / commitdiff
