Linux third day: Linux Help, File system

Linux third day: Linux Help, File system

Whatis display a short description of the command
Makewhatis CENTOS6 Production Database
MANDB CENTOS7 Production Database

Help Command Internal command
Man Bash internal command
Command--help-h External command
Man COMMAND User manual
Info COMMAND Information page
Readme
INSTALL
ChangeLog

Date--help
Date [-U|--UTC|--UNIVERSAL][MMDDHHMM[[CC]YY][.SS]]

X|y|z meaning x or Y or Z
-ABC meaning-a-b-C

/etc/man.config | man_db.conf configuration file
Man/-m/path/to/somewhere COMMAND: Search the man page at the specified location
[] Optional
<> must choose
A|b two Choose one
... Times

man-a keyword List all help
man-k keyword list matching pages
Space, ^v, ^f, ^f page to the end of the file
B, ^b the first page of the file
D, ^d to the end of the file half screen
U, ^u to file the first half screen
Q exit
# Jump to # line
1G back to file header

G turn to the end of the file
/keyword keyword-to-tail search is not case-sensitive
N Next
N Previous
? KEYWORD keyword-to-first search is not case-sensitive

Linux third day: Linux Help, File system