（一） 文件相关. PAGEREF _Toc323325472 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370032000000
1. 读取文件*.12的所有文件的第五到第七行. PAGEREF _Toc323325473 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370033000000
2. 去掉root:home:tele:password中的root:home PAGEREF _Toc323325474 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370034000000
3. 删除所有非字母开头的文件和文件夹. PAGEREF _Toc323325475 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370035000000
4. 查找指定目录已经失效的软链接. PAGEREF _Toc323325476 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370036000000
5. 查找指定目录已经失效的软链接并删除. PAGEREF _Toc323325477 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370037000000
6. 复制除了path文件夹的文件和目录. PAGEREF _Toc323325478 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370038000000
7. 删除以’-’开头的文件. PAGEREF _Toc323325479 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400370039000000
8. grep匹配多行‘abc\nefg’. PAGEREF _Toc323325480 \h 1
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380030000000
9. 文件1中有的，文件2中没有（文件本身已排序）. PAGEREF _Toc323325481 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380031000000
10. 文件1中有的，文件2中没有（文件本身已排序）. PAGEREF _Toc323325482 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380032000000
11. 文件1文件2中都有的（文件本身已排序）. PAGEREF _Toc323325483 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380033000000
（二） 时间相关. PAGEREF _Toc323325484 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380034000000
1. 获取一年前四个月后八天前的日期（GNU date）. PAGEREF _Toc323325485 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380035000000
2. 判断8位数的日期是否合法. PAGEREF _Toc323325486 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380036000000
3. crontab中的%字符. PAGEREF _Toc323325487 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380037000000
（三） 目录相关. PAGEREF _Toc323325488 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380038000000
1. 获取文件夹名/root/home (/root/home/tt.txt) PAGEREF _Toc323325489 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400380039000000
2. 获取文件名tt.txt (/root/home/tt.txt) PAGEREF _Toc323325490 \h 2
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003300320033003300320035003400390030000000
$ find . -name "*.12" -exec sed
-n '5,7p;8q' {} >>filea \;
$ cut -d: -f2- urfile
$ find . -mindepth 1 -name "[^a-zA-Z]*" |
xargs -I {} rm -rf {}
$ find
-L ur_path -type l
$ find -L
ur_path -type l –delete
$find . -prune path1-maxdepth 1 -exec
cp {} YYY \;
rm - - -foo
rm ./-foo
匹配多行‘abc\nefg’
grep -A1 'abc$'
filename | grep -B1 '^efg'
comm -23 file1 file2
comm -13 file1 file2
comm -12 file1 file2
12.
后个月文件的第五到第七
#date -d"-1 year +4
month +8 day" +%Y-%m-%d
[[ `date -d'20101050' &>/dev/null` ]]
&& echo ok||echo no
中的%字符
在crontab中%字符被认为是换行，所以你的命令中有%时，在crontab中要加\转义
30 * * * * date '+%D'
>datefile
是错误的
正确的应该是
30 * * * * date '+\%D'
>datefile
4.
dirname path
basename path # basename path .txt 也去掉后缀
