cmp
rose1 发表于 2020-08-25 09:15浏览次数：
在类似Unix的操作系统上，cmp命令用于逐字节比较两个文件。 如果发现差异，它将报告找到第一个差异的字节和行号。 如果未找到差异，则默认情况下，cmp不返回任何输出。
本文档介绍了cmp的GNU / Linux版本。
On Unix-like operating systems, the cmp command is used to compare two files byte by byte. If a difference is found, it reports the byte and line number where the first difference is found. If no differences are found, by default, cmp returns no output.
This document covers the GNU/Linux version of cmp.
目录：
1 cmp 运行系统环境
2 cmp 语法
3 cmp 例子
cmp 运行系统环境
cmp 语法
cmp [OPTION]... FILE1 [FILE2 [SKIP1 [SKIP2]]]
选件
可选的SKIP1和SKIP2指定每个文件开头要跳过的字节数（默认为零）。
跳过值后可以跟以下乘法后缀：
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kB
|
kilobytes
|
1000
|
|
K
|
kibibytes
|
1024
|
|
MB
|
megabytes
|
1,000,000
|
|
M
|
mebibytes
|
1,048,576
|
|
GB
|
gigabytes
|
1,000,000,000
|
|
G
|
gibibytes
|
1,073,741,824
|
...对于T，P，E，Z，Y等等。
如果FILE指定为' - '或未指定，则从标准输入读取数据。如果输入相同，则cmp的退出状态为0；如果输入不同，则为1；如果程序遇到问题，则为2。
附加选项：
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-b, --print-bytes
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打印不同的字节。
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-i, --ignore-initial=SKIP
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跳过两个文件的前一个跳过字节。
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-i, --ignore-initial=SKIP1:SKIP2
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跳过第一SKIP1的字节FILE1和第一SKIP2字节FILE2。
|
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-l, --verbose
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输出字节数和不同的字节值。
|
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-n, --bytes=LIMIT
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比较最多LIMIT个字节。
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-s, --quiet, --silent
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禁止所有正常输出。
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|
--help
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显示帮助消息并退出。
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|
-v, --version
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输出版本信息并退出。
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cmp [OPTION]... FILE1 [FILE2 [SKIP1 [SKIP2]]]
Options
The optional SKIP1 and SKIP2 specify the number of bytes to skip at the beginning of each file (zero by default).
SKIP values may be followed by the following multiplicative suffixes:
|
kB
|
kilobytes
|
1000
|
|
K
|
kibibytes
|
1024
|
|
MB
|
megabytes
|
1,000,000
|
|
M
|
mebibytes
|
1,048,576
|
|
GB
|
gigabytes
|
1,000,000,000
|
|
G
|
gibibytes
|
1,073,741,824
|
...and so on for T, P, E, Z, Y.
If a FILE is specified as '-' or not specified, data is read from standard input. cmp's exit status is 0 if inputs are the same, 1 if different, or 2 if the program encounters a problem.
Additional options:
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-b, --print-bytes
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Print differing bytes.
|
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-i, --ignore-initial=SKIP
|
Skip first SKIP bytes of both files.
|
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-i, --ignore-initial=SKIP1:SKIP2
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Skip first SKIP1 bytes of FILE1 and first SKIP2 bytes of FILE2.
|
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-l, --verbose
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Output byte numbers and differing byte values.
|
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-n, --bytes=LIMIT
|
Compare at most LIMIT bytes.
|
|
-s, --quiet, --silent
|
Suppress all normal output.
|
|
--help
|
Display a help message and exit.
|
|
-v, --version
|
Output version information and exit.
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cmp 例子
cmp file1.txt file2.txt
将file1与file2进行比较，逐字节读取每个文件并进行比较，直到其中一个字节对不相等。找到差异后，它将在文件中输出找到差异的位置，然后退出。输出示例：
file.txt file2.txt differ: char 1011, line 112
cmp file1.txt file2.txt
Compares file1 to file2, reading each file byte-by-byte and comparing them until one of the byte pairs is not equal. When a difference is found, it will output the location in the file where the difference was found, and exit. Example output:
file.txt file2.txt differ: char 1011, line 112