#目標:本文提供一些關於如何搜尋指定目錄或整個檔案系統中那些包含指定單字或字串的檔案。
難度:容易
約定:
第一個範例讓我們來搜尋 /etc/ 目錄下所有包含 stretch 字串的文件,但不去搜尋其中的子目錄:
# grep -s stretch /etc/* /etc/os-release:PRETTY_NAME="Debian GNU/Linux 9 (stretch)" /etc/os-release:VERSION="9 (stretch)"
grep 的 -s 選項會在發現不存在或無法讀取的檔案時隱藏報錯資訊。結果顯示除了檔案名稱之外,還有包含請求字串的行也被一起輸出了。
上面案例中忽略了所有的子目錄。所謂遞歸搜尋就是指同時搜尋所有的子目錄。
下面的指令會在 /etc/ 及其子目錄中搜尋包含 stretch 字串的檔案:
# grep -R stretch /etc/* /etc/apt/sources.list:# deb cdrom:[Debian GNU/Linux testing _Stretch_ - Official Snapshot amd64 NETINST Binary-1 20170109-05:56]/ stretch main /etc/apt/sources.list:#deb cdrom:[Debian GNU/Linux testing _Stretch_ - Official Snapshot amd64 NETINST Binary-1 20170109-05:56]/ stretch main /etc/apt/sources.list:deb http://ftp.au.debian.org/debian/ stretch main /etc/apt/sources.list:deb-src http://ftp.au.debian.org/debian/ stretch main /etc/apt/sources.list:deb http://security.debian.org/debian-security stretch/updates main /etc/apt/sources.list:deb-src http://security.debian.org/debian-security stretch/updates main /etc/dictionaries-common/words:backstretch /etc/dictionaries-common/words:backstretch's /etc/dictionaries-common/words:backstretches /etc/dictionaries-common/words:homestretch /etc/dictionaries-common/words:homestretch's /etc/dictionaries-common/words:homestretches /etc/dictionaries-common/words:outstretch /etc/dictionaries-common/words:outstretched /etc/dictionaries-common/words:outstretches /etc/dictionaries-common/words:outstretching /etc/dictionaries-common/words:stretch /etc/dictionaries-common/words:stretch's /etc/dictionaries-common/words:stretched /etc/dictionaries-common/words:stretcher /etc/dictionaries-common/words:stretcher's /etc/dictionaries-common/words:stretchers /etc/dictionaries-common/words:stretches /etc/dictionaries-common/words:stretchier /etc/dictionaries-common/words:stretchiest /etc/dictionaries-common/words:stretching /etc/dictionaries-common/words:stretchy /etc/grub.d/00_header:background_image -m stretch `make_system_path_relative_to_its_root "$GRUB_BACKGROUND"` /etc/os-release:PRETTY_NAME="Debian GNU/Linux 9 (stretch)" /etc/os-release:VERSION="9 (stretch)"
#上面 grep 指令的案例中列出的是所有包含字串 stretch 的檔案。也就是說包含 stretches , stretched 等內容的行也會被顯示。使用 grep 的 -w 選項會只顯示包含特定單字的行:
# grep -Rw stretch /etc/* /etc/apt/sources.list:# deb cdrom:[Debian GNU/Linux testing _Stretch_ - Official Snapshot amd64 NETINST Binary-1 20170109-05:56]/ stretch main /etc/apt/sources.list:#deb cdrom:[Debian GNU/Linux testing _Stretch_ - Official Snapshot amd64 NETINST Binary-1 20170109-05:56]/ stretch main /etc/apt/sources.list:deb http://ftp.au.debian.org/debian/ stretch main /etc/apt/sources.list:deb-src http://ftp.au.debian.org/debian/ stretch main /etc/apt/sources.list:deb http://security.debian.org/debian-security stretch/updates main /etc/apt/sources.list:deb-src http://security.debian.org/debian-security stretch/updates main /etc/dictionaries-common/words:stretch /etc/dictionaries-common/words:stretch's /etc/grub.d/00_header:background_image -m stretch `make_system_path_relative_to_its_root "$GRUB_BACKGROUND"` /etc/os-release:PRETTY_NAME="Debian GNU/Linux 9 (stretch)" /etc/os-release:VERSION="9 (stretch)"
上面的命令都会产生多余的输出。下一个案例则会递归地搜索 etc 目录中包含 stretch 的文件并只输出文件名:
# grep -Rl stretch /etc/* /etc/apt/sources.list /etc/dictionaries-common/words /etc/grub.d/00_header /etc/os-release
默认情况下搜索是大小写敏感的,也就是说当搜索字符串 stretch 时只会包含大小写一致内容的文件。
通过使用 grep 的 -i 选项,grep 命令还会列出所有包含 Stretch , STRETCH , StReTcH 等内容的文件,也就是说进行的是大小写不敏感的搜索。
# grep -Ril stretch /etc/* /etc/apt/sources.list /etc/dictionaries-common/default.hash /etc/dictionaries-common/words /etc/grub.d/00_header /etc/os-release
grep 命令也可以只在指定文件中进行搜索。比如,我们可以只在配置文件(扩展名为.conf)中搜索指定的文本/字符串。 下面这个例子就会在 /etc 目录中搜索带字符串 bash 且所有扩展名为 .conf 的文件:
# grep -Ril bash /etc/*.conf OR # grep -Ril --include=\*.conf bash /etc/* /etc/adduser.conf
类似的,也可以使用 --exclude 来排除特定的文件:
# grep -Ril --exclude=\*.conf bash /etc/* /etc/alternatives/view /etc/alternatives/vim /etc/alternatives/vi /etc/alternatives/vimdiff /etc/alternatives/rvim /etc/alternatives/ex /etc/alternatives/rview /etc/bash.bashrc /etc/bash_completion.d/grub /etc/cron.daily/apt-compat /etc/cron.daily/exim4-base /etc/dictionaries-common/default.hash /etc/dictionaries-common/words /etc/inputrc /etc/passwd /etc/passwd- /etc/profile /etc/shells /etc/skel/.profile /etc/skel/.bashrc /etc/skel/.bash_logout
跟文件一样,grep 也能在搜索时排除指定目录。 使用 --exclude-dir 选项就行。
下面这个例子会搜索 /etc 目录中搜有包含字符串 stretch 的文件,但不包括 /etc/grub.d 目录下的文件:
# grep --exclude-dir=/etc/grub.d -Rwl stretch /etc/* /etc/apt/sources.list /etc/dictionaries-common/words /etc/os-release
-n 选项还会显示指定字符串所在行的行号:
# grep -Rni bash /etc/*.conf /etc/adduser.conf:6:DSHELL=/bin/bash
最后这个例子使用 -v 来列出所有不包含指定字符串的文件。
例如下面命令会搜索 /etc 目录中不包含 stretch 的所有文件:
# grep -Rlv stretch /etc/*
以上是使用 grep 尋找所有包含指定文字的文件的詳細內容。更多資訊請關注PHP中文網其他相關文章!