unix 下的C开发手册,还用详细的例程。

																				split																The Single UNIX ® Specification, Version 2				Copyright © 1997 The Open Group												 NAME				split - split files into pieces				 SYNOPSIS												split [-l line_count][-a suffix_length][file[name]]								split -b n[k|m][-a suffix_length][file[name]]								split [-line_count][-a suffix_length][file[name]]												 DESCRIPTION				The				split				utility reads an				input file and writes one or more output files.				The default size of each output file is 1000 lines.				The size of the output files can be modified by				specification of the				-b				or				-l				options.				Each output file is created with a unique suffix.				The suffix consists of exactly				suffix_length				lower-case letters from the				POSIX locale.				The letters of the suffix are used as if they				were a base-26 digit system, with the first suffix to be				created consisting of all				a				characters, the second with a				b				replacing				the last				a,				and so on, until a name of all				z				characters				is created.				By default, the names of the output files are				x,				followed by a two-character suffix from the character set as				described above, starting with				aa,				ab,				ac,				and so on, and continuing until the suffix				zz,				for a maximum of 676 files.								If the number of files required				exceeds the maximum allowed by the suffix length provided,				such that the last allowable file would				be larger than the requested size, the				split				utility will fail after creating the last file				with a valid suffix;				split				will not delete the files it created				with valid suffixes.				If the file limit is not exceeded, the last file created will contain				the remainder of the input file, and may be smaller than the				requested size.				 OPTIONS				The				split				utility supports the XBD specification, Utility Syntax Guidelines  				except that the obsolescent version allows a multi-digit option,				-line_count.								The following options are supported:												-a suffix_length								Use				suffix_length				letters to form the suffix portion of the filenames				of the split file.				If				-a				is not specified, the default suffix length is two.				If the sum of the				name				operand and the				suffix_length				option-argument would create a filename exceeding				{NAME_MAX}				bytes, an error will result;				split				will exit with a diagnostic message				and no files will be created.								-b n				Split a file into pieces				n				bytes in size.								-b nkSplit a file into pieces				n*1024				bytes in size.								-b nmSplit a file into pieces				n*1048576				bytes in size.												-l line_count								-line_count				Specify the number of lines in each resulting file piece.				The				line_count				argument is an unsigned decimal integer.				The default is 1000.				If the input does not end with a				newline character,				the partial line will be included in the last output file.												 OPERANDS				The following operands are supported:												fileThe pathname of the ordinary file to be split.				If no input file is given				or				file				is "-", the standard input will be used.												nameThe prefix to be used for each of the files resulting from				the split operation.				If no				name				argument is given,				x				will be used as the prefix of the output files.				The combined length of the basename of				prefix				and				suffix_length				cannot exceed				{NAME_MAX}				bytes; see the OPTIONS section.												 STDIN				See the INPUT FILES section.				 INPUT FILES				Any file can be used as input.				 ENVIRONMENT VARIABLES				The following environment variables affect the execution of				split:												LANGProvide a default value for the internationalisation variables				that are unset or null.				If				LANG				is unset or null, the corresponding value from the				implementation-dependent default locale will be used.				If any of the internationalisation variables contains an invalid setting, the				utility will behave as if none of the variables had been defined.								LC_ALL				If set to a non-empty string value,				override the values of all the other internationalisation variables.								LC_CTYPE				Determine the				locale for the interpretation of sequences of bytes of text data as				characters (for example, single- as opposed to multi-byte characters				in arguments and input files).								LC_MESSAGES				Determine the locale that should be used to affect				the format and contents of diagnostic				messages written to standard error.								NLSPATH				Determine the location of message catalogues				for the processing of				LC_MESSAGES .												 ASYNCHRONOUS EVENTS				Default.				 STDOUT				Not used.				 STDERR				Used only for diagnostic messages.				 OUTPUT FILES				The output files contain portions of the original input file,				otherwise unchanged.				 EXTENDED DESCRIPTION				None.				 EXIT STATUS				The following exit values are returned:												0Successful completion.								>0An error occurred.												 CONSEQUENCES OF ERRORS				Default.				 APPLICATION USAGE				None.								 EXAMPLES				In the following examples				foo				is a text file that contains 5000 lines.																Create five files,				xaa,				xab,				xac,				xad				and				xae:												split foo																				Create five files, but the suffixed portion of the created				files consists of three letters,				xaaa,				xaab,				xaac,				xaad				and				xaae:												split -a 3 foo																				Create three files with four-letter suffixes				and a supplied prefix,				bar_aaaa,				bar_aaab				and				bar_aaac:												split -a 4 -l 2000 foo bar_																				Create as many files as are necessary to contain at most				20*1024 bytes, each with the default prefix of				x				and a five-letter suffix:												split -a 5 -b 20k foo																				 FUTURE DIRECTIONS				None.				 SEE ALSO				csplit.												UNIX ® is a registered Trademark of The Open Group.				Copyright © 1997 The Open Group				 [ Main Index | XSH | XCU | XBD | XCURSES | XNS ]