在KDE或Gnome桌面下，我可以很好地搜索所有手册页中的特定命令或短语。
我通过ssh会话登录到远程服务器。
如何在Linux Shell提示符下搜索所有手册页以查找特定命令？
您需要使用以下命令来搜索手册页：

apropos命令

apropos命令在一组包含系统命令简短描述的数据库文件中搜索关键字，并在屏幕上显示结果。
语法如下：

apropos keyword
apropos "string or phrase"
apropos -s 1 delete

apropos命令示例

要搜索与比较操作有关的命令/功能，请执行：

$ apropos compare

输出示例：

[ (1)                - check file types and compare values
bcmp (3)             - compare byte sequences
bzcmp (1)            - compare bzip2 compressed files
bzdiff (1)           - compare bzip2 compressed files
cmp (1)              - compare two files byte by byte
comm (1)             - compare two sorted files line by line
compare (1)          - mathematically and visually annotate the difference between an image and its reconstruction.
diff (1)             - compare files line by line
diff3 (1)            - compare three files line by line
git-diff-files (1)   - Compares files in the working tree and the index
git-diff-index (1)   - Compares content and mode of blobs between the index and repository
git-diff-tree (1)    - Compares the content and mode of blobs found via two tree objects
infocmp (1)          - compare or print out terminfo descriptions
mcomp (1)            - Compares two files using mtools
memcmp (3)           - compare memory areas
msgcmp (1)           - compare message catalog and template
ndiff (1)            - Utility to compare the results of Nmap scans
ntfscmp (8)          - compare two NTFS filesystems and tell the differences
pthread_equal (3)    - compare thread IDs
strcasecmp (3)       - compare two strings ignoring case
strcmp (3)           - compare two strings
strcoll (3)          - compare two strings using the current locale
strncasecmp (3)      - compare two strings ignoring case
strncmp (3)          - compare two strings
strverscmp (3)       - compare two version strings
test (1)             - check file types and compare values
wcscasecmp (3)       - compare two wide-character strings, ignoring case
wcscmp (3)           - compare two wide-character strings
wcsncasecmp (3)      - compare two fixed-size wide-character strings, ignoring case
wcsncmp (3)          - compare two fixed-size wide-character strings
wmemcmp (3)          - compare two arrays of wide-characters
xzcmp (1)            - compare compressed files
xzdiff (1)           - compare compressed files
zcmp (1)             - compare compressed files
zdiff (1)            - compare compressed files

搜索字符串

搜索命令以删除文件，执行：

$ apropos "remove file"

输出示例：

rm                   (1)  - remove files or directorie

手册页中的搜索特定部分

要仅搜索给定的手册部分，请使用-s选项：

apropos -s 1 compare

输出示例：

[ (1)                - check file types and compare values
bzcmp (1)            - compare bzip2 compressed files
bzdiff (1)           - compare bzip2 compressed files
cmp (1)              - compare two files byte by byte
comm (1)             - compare two sorted files line by line
compare (1)          - mathematically and visually annotate the difference between an image and its reconstruction.
diff (1)             - compare files line by line
diff3 (1)            - compare three files line by line
git-diff-files (1)   - Compares files in the working tree and the index
git-diff-index (1)   - Compares content and mode of blobs between the index and repository
git-diff-tree (1)    - Compares the content and mode of blobs found via two tree objects
infocmp (1)          - compare or print out terminfo descriptions
mcomp (1)            - Compares two files using mtools
msgcmp (1)           - compare message catalog and template
ndiff (1)            - Utility to compare the results of Nmap scans
test (1)             - check file types and compare values
xzcmp (1)            - compare compressed files
xzdiff (1)           - compare compressed files
zcmp (1)             - compare compressed files
zdiff (1)            - compare compressed files

基于正则表达式的搜索

您可以使用-r选项强制apropos将每个关键字解释为正则表达式：

$ apropos -r scanf

输出示例：

fscanf (3)           - input format conversion
scanf (3)            - input format conversion
sscanf (3)           - input format conversion
Video::DVDRip::CPAN::Scanf (3pm) - emulate sscanf() of the C library
vfscanf (3)          - input format conversion
vscanf (3)           - input format conversion
vsscanf (3)          - input format conversion

man -K命令

-K选项传递给man命令，以在所有手册页中搜索指定的字符串。
语法如下：

man -K keyword
man -K "string or phrase"

在所有手册页中搜索fopen字，执行：

$ man -K "fopen"

输出：

/usr/share/man/en/man3/fclose.3.gz? [ynq]

输入y打开/显示手册页，输入n继续搜索，输入q退出搜索。
这是蛮力搜索，可能会花费一些时间。
因此，使用以下语法来指定手册页部分(1-7)有助于：

$ man -s 3 -K "open"

或者

$ man -s 8 -K "user"

请注意，上述命令也可以与其他UNIX和* BSD一起使用，例如oses