杨贵福 - Page 156

根据分隔符按列cut（转载）

cut 使用 cut 工具，我们可以将构成文件中数据域的各个列分隔开来。默认的分隔符是制表符，-f 选项可以用来指定希望显示的域。举例来说，假设一个文本文件 "sample" 有三列，其内容如下所示：

one    two    three
four   five   six
seven  eight  nine
ten    eleven twelve

现在执行下面的命令：

# cut -f2 sample

这会返回：

two
five
eight
eleven

如果将这个命令修改成：

# cut -f1, 3 sample

这会返回下面的不同结果：

one    three
four   six
seven  nine
ten    twelve

这个命令有几个命令行选项。除了 -f 之外，我们还应该熟悉下面两个选项：

-c ―― 允许我们指定字符而不是域。
-d ―― 允许我们指定其他分隔符，而不是制表符。

____________________________________
cut：两个实际例子 ls -l 命令可以显示某个目录中所有文件的权限、链接个数、属主、组、大小、日期和文件名 ―― 这些都是以空格分隔开的。如果我们对大部分域都不感兴趣，而是只希望了解文件属主的信息，可以使用下面的命令：

# ls -l | cut -d" " -f5
root
562
root
root
 root
root
root
root

这个命令只会显示文件属主（第 5 个域），而会忽略其他域。如果您知道文件属主信息开始的第一个字符的确切位置，可以使用 -c 选项来显示文件属主的第一个字符。假设它是从第 16 个字符开始的，下面这个命令就返回第 16 个字符，这是文件属主名的第一个字符。

# ls -l | cut -c16
r

r
r
r
r
r
r

如果我们再假设大部分用户都使用最多 8 个字符作为自己的用户名，那么我们就可以使用下面的命令：

# ls -l | cut -c16-24

这会返回用户名域的那些项。现在假设文件名是从第 55 个字符开始的，但是我们无法确定文件名会连续占用多少个字符，因为有些文件名可能会比其他文件名长很多。解决方案是从第 55 个字符开始，但却不指定结束字符（这意味着我们要截取该行中所有剩余的内容），如下所示：

# ls -l | cut -c55-
a.out
cscope-15.5
cscope-15.5.tar
cscope.out 
memo
search_items
test.c
test.s

现在我们来考虑另外一种情况。为了获得系统中所有用户的清单，我们可以从前面使用过的 /etc/passwd 文件中提取第一个域：

# cut -d":" -f1 /etc/passwd
root
bin
daemon
adm 
lp
sync
shutdown
halt
mail
news
uucp
operator

要搜集用户名及其对应的主目录，我们可以提取第 1 个和第 6 个域的内容：

# cut -d":" -f1,6 /etc/passwd
root:/root
bin:/bin
 daemon:/sbin
adm:/var/adm
lp:/var/spool/lpd
sync:/sbin
shutdown:/sbin
halt:/sbin
mail:/var/spool/mail
news:/etc/news
uucp:/var/spool/uucp
operator:/root

cut的使用方法
　　名称：cut 　　使用权限：所有使用者　　用法：cut -cnum1 -num2 filename 　　说明：显示每行从开头算起 num1 到 num2 的文字。　　范例：　　shell>> cat example 　　test2 　　this is test1 　　shell>> cut -c0 -6 example ## print 开头算起前 6 个字节　　test2 　　this i

npipe

E:temp>npipe
Usage: npipe [OPTIONS] [INPUT] [OUTPUTS] [FILE FLAGS] [CONVERSIONS]
Input parameters can appear in any order, file flags affect only the next
file/flag/handle/section/object specified on the command line
-t, --tee
        Copy INPUT to STDOUT
-s, --stderrtee
        Copy INPUT to STDERR
-n handle-num, --handle handle-num
        Copy INPUT to handle: handle-num
-e error-file, --error-file error-file
        Send errors to file: error-file
-a append-file, --append-file append-file
        Append INPUT to file: append-file
-i input-file, --input-file input-file
        Read INPUT from file: input-file
-N handle-num, --input-handle handle-num
        Read INPUT from handle: handle-num
-D ntapi-file, --device-input ntapi-file
        Read INPUT from native api/kernel file: ntapi-file
-d ntapi-file, --device-output ntapi-file
        Copy INPUT to native api/kernel file: ntapi-file
-V, -VV, -VVV, -VVVV
        Increasing verbosity, by default only parameter error info
-b buffer-length, --buffer-length buffer-length
        Set the IO buffer size (default is 64k, unless console handle IO
        is taking place, in which case it is 256)
-w, --wait
        Wait for all pipes to be connected to before starting transfer
-B, --block-read
        Read an entire buffer before writing
        Likely only affects pipes or other communication handles
-m max-bytes, --maximum max-bytes
        Read a maximum of max-bytes from INPUT
-c conversion-function, --convert conversion-function
        Converts the buffer using one of the following functions:
        All output commands after this point will be processed after the
        conversion, those before will be unaffected.
        l       ANSI To Lower Case
        L       Unicode To Lower Case
        u       ANSI To Upper Case
        U       Unicode To Upper Case
        c       Clean non-ASCII to space
        c:l     Clean non-ASCII to letter l
        cnum    Clean non-ASCII to ASCII char num
        c-      Delete non-ASCII
        O       ANSI to OEM
        A       OEM to ANSI
        w       ANSI to Unicode
        W       ANSI to Unicode, with BOM
        a       Unicode to ANSI
        s[num] Swap order of every num bytes, default 2, where num is a power
                of two
        hb[+][-]Binary to Hex by byte [with text dump] [without address dump]
        hw[+][-]Binary to Hex by word [with text dump] [without address dump]
        hd[+][-]Binary to Hex by dword [with text dump] [without address dump]
        hr[+]   Binary to Hex by byte raw dump [with spaces]
-h, -?, --help
        Display this help
-v, --version
        Display version info
--credits
        Display program credits
-P, --progress
        Displays a progress bar on the active console screen buffer (not STDOUT
        or STDERR)
-R, --report
        Print a status report to the error handle (default STDERR, set with -e)
        This is overriden by the progress-bar flag (-P).
-O [queue length], --overlapped [queue length]
        Reads from the input file (not file mapping) using asynchronous
        overlapped IO.
        This will probably improve the overall read/process speed
        This is incompatible with the block-read flag (-B), and file mapping
        inputs (-F)
        'Queue length' defaults to 16, and must be between 1 and 64.
-Q, --overlapped-output
        Outputs to the last output handle in the chain using asynchronous
        overlapped IO.
        This is incompatible with file mapping outputs
        This activates overlapped read IO (-O above)
-X, --always-read
        Read input even if no output specified

Flags which affect the next file on the command line
-W, --file-share-write
        Open with FILE_SHARE_WRITE
-F, --file-mapping
        Treat as a named file mapping object (cannot be a pipe)
        For best performance: ensure that the buffer size and the skip offset
        are a multiple of the page size, usually 4k.
-p, --persistent
        Continue writing to next handle, even if write errors occur
        Read unmapable/unreadable sections as blank
-S skip-bytes, --skip skip-bytes
        Skip the first skip-bytes bytes of the file, (not pipe)
Flags which affect the next file on the command line (pipe only)
-z    Force connection to existing pipes rather than create a new pipe
-Z    Force creation of new pipes rather than connection to existing pipe

Pipe names must be in the format: .pipe[[path]name]
INPUT defaults to STDIN
/ may be used instead of -
Number may be prefixed with 0x for hexadecimal, and postfixed with the following
SI prefixes: k,M,G,T,P,E
These stand for increasing powers of 2^10 (1024) and can be used to specify kilo
bytes, megabytes, etc.
One letter arguments may be clumped, however only the last argument in the clump
may have an argument.
eg. -V -V -t -s -b64k <--> -VVtsb64k

Example: npipe -tsVVVVwm64k -FpD DevicePhysicalMemory out -chr -a outputfile -
Z .pipepipe1
Outputs to STDOUT,STDERR. Very verbosely. Waits for all pipes. Read max 64kB (65
536 bytes). Opens DevicePhysicalMemory as a ntapi file mapping object and pers
istently reads from it. Outputs to file: 'out'. Converts output to a raw hexdump
, affects following two output commands. Appends to file: 'outputfile'. Always c
reates, and outputs on pipe: 'pipe1'.

E:temp>npipe -c hr+ -i writer.exe outputs