Objektif: Artikel ini menyediakan beberapa maklumat tentang cara mencari fail yang mengandungi perkataan atau rentetan tertentu dalam direktori tertentu atau keseluruhan sistem fail.
Kesukaran: Mudah
Janji:
stretch dalam direktori /etc/, tetapi jangan cari subdirektori:
# grep -s stretch /etc/* /etc/os-release:PRETTY_NAME="Debian GNU/Linux 9 (stretch)" /etc/os-release:VERSION="9 (stretch)"
grep akan menyembunyikan mesej ralat apabila fail yang tidak wujud atau tidak boleh dibaca ditemui. Keputusan menunjukkan bahawa sebagai tambahan kepada nama fail, baris yang mengandungi rentetan permintaan juga dikeluarkan.
Arahan berikut akan mencari
/etc/ dan subdirektorinya untuk fail yang mengandungi rentetan stretch:
# 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 "$GRUB_BACKGROUND"` /etc/os-release:PRETTY_NAME="Debian GNU/Linux 9 (stretch)" /etc/os-release:VERSION="9 (stretch)"
grep di atas menyenaraikan semua fail yang mengandungi rentetan stretch. Maksudnya, garisan yang mengandungi regangan, regang, dsb. juga akan dipaparkan. Menggunakan pilihan -w grep hanya akan menunjukkan baris yang mengandungi perkataan tertentu:
# grep -Rw stretch /etc/* /etc/apt/sources.list:# deb cdrom:[Debian GNU/Linux testing _Stretch_ - Official Snapshot amd64 NETINST Binary-1 20170109-05:56]/ stretch main /etc/apt/sources.list:#deb cdrom:[Debian GNU/Linux testing _Stretch_ - Official Snapshot amd64 NETINST Binary-1 20170109-05:56]/ stretch main /etc/apt/sources.list:deb http://ftp.au.debian.org/debian/ stretch main /etc/apt/sources.list:deb-src http://ftp.au.debian.org/debian/ stretch main /etc/apt/sources.list:deb http://security.debian.org/debian-security stretch/updates main /etc/apt/sources.list:deb-src http://security.debian.org/debian-security stretch/updates main /etc/dictionaries-common/words:stretch /etc/dictionaries-common/words:stretch's /etc/grub.d/00_header:background_image -m stretch `make_system_path_relative_to_its_root "$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/*
Atas ialah kandungan terperinci Gunakan grep untuk mencari semua fail yang mengandungi teks yang ditentukan. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!
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