Linux文本搜索比较命令-- grep/diff

---- GREP（1）

NAME：grep - Search for PATTERN in each FILE or standard input.

PATTERN is, by default, a basic regular expression (BRE) 正则表达式

选项说明：

        -n，--line-number : print line number with output files 

        -s，--no-messages : suppress error messages. 不显示错误信息

        -v， --invert-match : select non-matching lines 取反操作，选择不匹配的输出。

        -A，--after-context=NUM : print NUM lines of trailing context 输出context后的NUM行

        -B，--before-context=NUM
: print NUM lines of leading context

        -C，--context=NUM ： print NUM lines of output context，上下NUM行都输出

        -NUM      same as --context=NUM



命令cut用于基于列处理文本

-d，--delimiter 指定分割字符，默认是Tab

-f，--fields 指定输出的列号，某一行的域

-c，--character 基于字符进行分割



-d：表示以：作为分隔符。

-c3-10表示显示第3～10个字符。

[yanxia.dong@eslruntime07 exercise]$ grep -n yanxia.dong /etc/passwd
54:yanxia.dong:x:508:100::/home/yanxia.dong:/bin/bash
[yanxia.dong@eslruntime07 exercise]$ grep -n -A3 yanxia.dong /etc/passwd
54:yanxia.dong:x:508:100::/home/yanxia.dong:/bin/bash
55-hailong.yu:x:509:100::/home/hailong.yu:/bin/tcsh
56-zezeng.feng:x:510:100::/home/zezeng.feng:/bin/bash
57-eslshare:x:511:100::/home/eslshare:/sbin/nologin
[yanxia.dong@eslruntime07 exercise]$ grep -n -B3 yanxia.dong /etc/passwd
51-feifan.wang:x:505:100::/home/feifan.wang:/bin/bash
52-tao.gao:x:506:100::/home/tao.gao:/bin/csh
53-mengjiao.liu:x:507:100::/home/mengjiao.liu:/bin/bash
54:yanxia.dong:x:508:100::/home/yanxia.dong:/bin/bash
[yanxia.dong@eslruntime07 exercise]$ grep -n -C3 yanxia.dong /etc/passwd
51-feifan.wang:x:505:100::/home/feifan.wang:/bin/bash
52-tao.gao:x:506:100::/home/tao.gao:/bin/csh
53-mengjiao.liu:x:507:100::/home/mengjiao.liu:/bin/bash
54:yanxia.dong:x:508:100::/home/yanxia.dong:/bin/bash
55-hailong.yu:x:509:100::/home/hailong.yu:/bin/tcsh
56-zezeng.feng:x:510:100::/home/zezeng.feng:/bin/bash
57-eslshare:x:511:100::/home/eslshare:/sbin/nologin
[yanxia.dong@eslruntime07 exercise]$ grep -n -1 yanxia.dong /etc/passwd
53-mengjiao.liu:x:507:100::/home/mengjiao.liu:/bin/bash
54:yanxia.dong:x:508:100::/home/yanxia.dong:/bin/bash
55-hailong.yu:x:509:100::/home/hailong.yu:/bin/tcsh

---- DIFF（1）

NAME：diff - compare files line by line

OPTION:

        -i --ignore-case : Ignore case differences in file contents.

        -E --ignore-tab-expansion : Ignore changes due to tab expansion. 忽略Tab键引起的变化

        -b --ignore-space-change : Ignore changes in the amount of the white space. 忽略空格数量的变化

        -w --ignore-all-space : Ignore all white space.忽略所有的空白

        -B --ignore-blank-lines : Ignore changes whose lines are all blank. 忽略空白行

        -c -C NUM --context [=NUM] : Output NUM (default 3) lines of copied context.

        -u -U NUM --unified [=NUM] : Output NUM (default 3) lines of unified context. 统一显示比较信息