man echo works. but out of curiosity, does echo have something similar to a
Assuming you are using bash,
echo is a shell builtin (which you can see by running
type echo). That means the man-page you want to read is
man bash. Or you can get help on bash builtins and keywords with the
help builtin, e.g.
The information you see when you run
man echo, is for the external
echo command, installed by GNU coreutils. (
type -a echo).
To learn bash, read http://mywiki.wooledge.org/BashGuide
There are two
echo The built-in command and another one, an executable placed in /bin/echo
The built-in (this is the default one) hasn't any help options far beyond the
help echo built-in. Any flags placed and not listed there are presented as command result and there's no help command.
In the executable version instead
/bin/echo there's a
--help flag which prints usage. but you must call
Other way would be using whatis bash command for example.
whatis echo >>>> shows as following echo (1) - display a line of text
According to Whatis manpage , it displays manual page descriptions. Such as
whatis whatis whatis (1) - display manual page descriptions
For Commands brief parameters or options try
--usage infront of them as
whatis --usage Usage: whatis [-dvrwl?V] [-C FILE] [-L LOCALE] [-m SYSTEM] [-M PATH] [-s LIST] [--debug] [--verbose] [--regex] [--wildcard] [--long] [--config-file=FILE] [--locale=LOCALE] [--systems=SYSTEM] [--manpath=PATH] [--sections=LIST] [--section=LIST] [--help] [--usage] [--version] KEYWORD...
Another excellent source is Ubuntu Manuals a.k.a manpage, just type to search what you want.
A suggestion if you try whatis in terminal and press Tab key successfully it will show
Display all 9747 possibilities? (y or n)
You can experiment depending on above possibilities.
Also there is apropos similar to
man -k keyword use to search the manual page names and descriptions.
You can also use whereis to locate the binary, source, and manual page files of a command as
whatis whereis whereis (1) - locate the binary, source, and manual page files for a command
You can refer this Extensive and excellent source at Ubuntu Command Line Wiki page such as [7. Beginners/BashScripting].
For External Source refer
An A-Z Index of the Bash command line for Linux explaining examples and Usage .
You could use the help command, as this is a bash builtin, this is a lot of help while scripting
[11:16:07 oyrm ~]$ help GNU bash, version 4.2.24(1)-release (x86_64-pc-linux-gnu) These shell commands are defined internally. Type `help' to see this list. Type `help name' to find out more about the function `name'. Use `info bash' to find out more about the shell in general. Use `man -k' or `info' to find out more about commands not in this list. ....
This banner is followed by a list of commands, as indicated in the banner. Try out
and I think you'll see that this is a nice, concise description of the application of the shell command