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root@E440:/home/zhangsy/opensrc/u-boot-2020.04# split --helpUsage: split [OPTION]... [FILE [PREFIX]]Output pieces of FILE to PREFIXaa, PREFIXab, ...;default size is 1000 lines, and default PREFIX is 'x'.With no FILE, or when FILE is -, read standard input.Mandatory arguments to long options are mandatory for short options too. -a, --suffix-length=N generate suffixes of length N (default 2) --additional-suffix=SUFFIX append an additional SUFFIX to file names -b, --bytes=SIZE put SIZE bytes per output file -C, --line-bytes=SIZE put at most SIZE bytes of records per output file -d use numeric suffixes starting at 0, not alphabetic --numeric-suffixes[=FROM] same as -d, but allow setting the start value -x use hex suffixes starting at 0, not alphabetic --hex-suffixes[=FROM] same as -x, but allow setting the start value -e, --elide-empty-files do not generate empty output files with '-n' --filter=COMMAND write to shell COMMAND; file name is $FILE -l, --lines=NUMBER put NUMBER lines/records per output file -n, --number=CHUNKS generate CHUNKS output files; see explanation below -t, --separator=SEP use SEP instead of newline as the record separator; '\0' (zero) specifies the NUL character -u, --unbuffered immediately copy input to output with '-n r/...' --verbose print a diagnostic just before each output file is opened --help display this help and exit --version output version information and exitThe SIZE argument is an integer and optional unit (example: 10K is 10*1024).Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (powers of 1000).CHUNKS may be: N split into N files based on size of input K/N output Kth of N to stdout l/N split into N files without splitting lines/records l/K/N output Kth of N to stdout without splitting lines/records r/N like 'l' but use round robin distribution r/K/N likewise but only output Kth of N to stdoutGNU coreutils online help: <http://www.gnu.org/software/coreutils/>Full documentation at: <http://www.gnu.org/software/coreutils/split>or available locally via: info '(coreutils) split invocation'
使用实例：
1.(按文件大小分割)比如我想将一个log文件切割成每个256k大小，后缀是2位数字结尾的子文件，子文件以child开头，则
split -a 2 -d -b 256k uboot.bin child -a 2 后缀是2位 -d 后缀是数字 -b 256k 每个文件最大256k uboot.bin child 需要切割的文件是uboot.bin，生成的子文件前缀是 "child"2.（按行数做分割）将一个文件分割成每1万行一个文件，后缀是2位，子文件以child开头
split -a 2 -l 10000 app.log child -a 2 后缀是2位 -l 10000 每10000行一个文件 app.log child 需要切割的文件是app.log，生成的子文件前缀是 "child"