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This article mainly explains "how to set the format and color of the SHEEL prompt in Linux". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn how Linux sets the format and color of the SHEEL prompt.

1. Understanding SP1 and SP2 parameters

The main prompt for command input in SP1:bash, such as "[oracle@prod ~] $".

SP2: when the command is very long, the prompt for newline typing defaults to ">".

You can enter a command in the terminal to view the system default parameters:

[root@prod ~] # echo $PS1

[\ u@\ h\ W]\ $

[root@prod ~] # echo $PS2

>

Or you can look at the set value:

[root@prod ~] # set | grep PS1

PS1=' [\ u@\ h\ W]\ $'

[root@prod ~] # set | grep PS2

PS2=' >'

If you need to see the definition of each part of the prompt parameter, you can execute the man bash command and find the PROMPTING section description:

PROMPTING

When executing interactively, bash displays the primary prompt PS1 when it is ready to read a command, and the secondary prompt PS2 when it needs more input to complete a command. Bash allows these prompt strings to be customized by inserting a number of backslash-escaped special characters that are decoded as follows:

\ an an ASCII bell character (07)

\ d the date in "Weekday Month Date" format (e.g., "Tue May 26")

\ d {format}

The format is passed to strftime (3) and the result is inserted into the prompt string; an empty format results in a locale-specific time representation.

The braces are required

\ e an ASCII escape character (033)

\ h the hostname up to the first'.

\ H the hostname

\ j the number of jobs currently managed by the shell

\ l the basename of the shell's terminal device name

\ nnewline

\ r carriage return

\ s the name of the shell, the basename of $0 (the portion following the final slash)

\ t the current time in 24-hour HH:MM:SS format

\ T the current time in 12-hour HH:MM:SS format

\ @ the current time in 12-hour am/pm format

\ A the current time in 24-hour HH:MM format

\ u the username of the current user

\ v the version of bash (e.g.2.00)

\ V the release of bash, version + patch level (e.g.2.00.0)

\ w the current working directory, with $HOME abbreviated with a tilde (uses the value of the PROMPT_DIRTRIM variable)

\ W the basename of the current working directory, with $HOME abbreviated with a tilde

\! The history number of this command

\ # the command number of this command

\ $if the effective UID is 0, a #, otherwise a $

\ nnn the character corresponding to the octal number nnn

\\ a backslash

\ [begin a sequence of non-printing characters, which could be used to embed a terminal control sequence into the prompt

\] end a sequence of non-printing characters

The command number and the history number are usually different: the history number of a command is its position in the history list, which may include commands restored from the history file (see HISTORY below), while the command number is the position in the sequence of commands executed during the current shell session. After the string is decoded, it is expanded via parameter expansion, command substitution, arithmetic expansion, and quote removal, subject to the value of the promptvars shell option (see the description of the shopt command under SHELL BUILTIN COMMANDS below).

Simply translate the sequence description:

\ an An ASCII ring character (07)

\ d date in "Weekday Month Date" format (e.g. "Tue May 26")

\ d {format} echoes the custom date format after passing a value to strftime

\ e ASCII escape character (033)

\ h the first part of the hostname, intercepted to the first'.'

\ h full name of the host

\ j number of processes managed in the current shell

\ l Base name of the end device name of the shell

\ nLine feed character

\ r carriage return

\ s name of shell, the name of the current script, excluding the path

\ t 24-hour time in HH:MM:SS format

\ t 12-hour time in HH:MM:SS format

12-hour time in am/pm format

\ a 12-hour time in HH:MM format

\ U user name of the current user

\ v version of bash (e.g. 2.00)

\ v bash version, including patch level (e.g. 2.00.0)

\ W current working directory, including paths

\ W Base name of the current working directory, excluding path

\! The history number of the current command

\ # Command number (as long as you type, it accumulates at each prompt)

\ $prompt "$" if you are not a superuser (root), or "#" if you are a superuser

\ nnn corresponds to the character of octal number nnn

\\ backslash

\ [start a series of non-print characters and embed the terminal control sequence into the prompt

\] end a series of non-print characters

two。 Test SP1 and SP2 parameters

Here are some tests on SP1 parameters (of course, users can adjust them according to their preferences):

[root@prod ~] # su-oracle

[oracle@prod ~] $set | grep PS1

PS1=' [\ u@\ h\ W]\ $'

[oracle@prod ~] $export PS1=' [\ u @\ h\ d\ W]\ $'

[oracle@prodSun Sep 10] $export PS1=' [\ u @\ h\ v\ W]\ $'

[oracle@prod 4.1a] $export PS1=' [\ u@\ h\ @\ W]\ $'

[oracle@prod 07:07 AM ~] $export PS1=' [\ u#\ h\ w]\ $'

[oracle#prod ~] $export PS1=' [my oracle zone- >\ h\ W]\ $'

[my oracle zone- > prod ~] $cd / u01/app/oracle

[my oracle zone- > prod oracle] $export PS1=' [\ u @\ h\ w]\ $'

[oracle@prod / u01/app/oracle] $export PS1=' [\ u@\ h\ W]\ $'

[oracle@prod oracle] $export PS1=' [you can write some information here...\ n\ u @\ h\ W]\ $'

[you can write some information here...

Oracle@prod oracle] $export PS1=' [\ u@\ h\ W]\ $'

[oracle@prod oracle] $

Of course, the SP2 parameter can also be set:

[oracle@prod oracle] $set | grep PS2

PS2=' >'

[oracle@prod oracle] $export PS2=' [\ u@\ h\ W] >'

[oracle@prod oracle] $ls

Admin cfgtoollogs checkpoints diag fast_recovery_area oradata product

[oracle@prod oracle] $ll\

[oracle@prod oracle] > fast_recovery_area/

Total 4

Drwxr-x---. 3 oracle oinstall 4096 Sep 9 09:46 PROD

[oracle@prod oracle] $export PS2='continue >'

[oracle@prod oracle] $ll\

Continue > fast_recovery_area/

Total 4

Drwxr-x---. 3 oracle oinstall 4096 Sep 9 09:46 PROD

[oracle@prod oracle] $export PS2=' >'

[oracle@prod oracle] $ll\

> fast_recovery_area

Total 4

Drwxr-x---. 3 oracle oinstall 4096 Sep 9 09:46 PROD

[oracle@prod oracle] $

3. Configure the color for the prompt

We can color the prompt by setting the PS1 and PS2 variables so that we can easily find the commands that have been entered on the page.

Set the format of the character sequence color to:\ e [Founding Bm

The color format of the ending character sequence is:\ e [0m

If you need to set the color for the character, you can set it like this:\ e [the part where the color needs to be set by FbomBm\ e [0m

Where F is the font color, and the serial number 30 "37" B is the background color, and the number is 40 "47.

The color information table is as follows:

F B

30 40 black

31 41 Red

32 42 Green

33 43 yellow

34 44 Blue

35 45 purplish red

36 46 turquoise

37 47 White

If you need to set up a special display, such as highlighting, you can set the character sequence color format\ e [Fash B in Fash Bm to 1, that is,\ e [1m], and then configure it with the color information, such as\ e [31th 40m\ e [1m].

The special display table is set as follows:

0 OFF, turn off color

1 highlight

4 show underline

5 flashing display

7 anti-white display

8 colors are not visible

By configuring the color parameters through the color information table and the setting special display table, the personalized color can be set for the terminal prompt.

For example, the prompt now is: PS1=' [\ u @\ h\ W]\ $'

Now make the following configuration:

Set the user name to red and black background, and highlight it, that is:\ e [31x 40m\ e [1m user name\ e [0m]

Set the hostname to a yellow and white background and show an underscore, that is:\ e [33 × 47m\ e [4m hostname\ e [0m]

Set the path to purplish red black background, that is:\ e [35 China 40m path\ e [0m]

The adjusted prompt is:

PS1=' [\ e [31x 40m\ e [1m\ u\ e [0m @\ e] [33x 47m\ e [4m\ h\ e [0m\ e [35x 40m\ W\ e [0m]\ $'

The effect is shown in the following figure:

Of course, users can test the SP1 and SP2 parameters many times to complete the color adjustment.

Note: in more cases, terminal display colors can be set through Xshell,SecureCRT, such as black words on white background, white words on black background, green words on black background, etc. The adjustment process can be combined with tools to obtain the most comfortable color configuration.

4. Configuration persistence save

The change set by executing the export command in the terminal is only valid for the current terminal, and opening another terminal after closing will fail. If you need to persist the changes, you need to configure the changes to the system configuration file.

Writing export statements to / etc/profile or / etc/bashrc takes effect for all users, and writing ~ / .bash_profile or ~ / .bashrc only works for the current user.

[root@prod ~] # echo "export PS1='\ e [33 countries 40m [\ u @\ h\ W]\ $\ e [0m'" > > / etc/bashrc

[root@prod ~] # cat / etc/bashrc | grep PS1

If ["$PS1"]; then

["$PS1" = "\\ s -\\ v\\ $"] & & PS1= "[\ u@\ h\ W]\ $"

# if ["$PS1"]; then

# PS1= "[\ u@\ h:\ l\ W]\\ $"

If ["$PS1"]; then

Export PS1='\ e [33th 40m [\ u @\ h\ W] $\ e [0m'

[root@prod ~] # source / etc/bashrc

In this way, you can keep the changes in effect permanently, and, through the configuration of colors, you can quickly locate the location of the last command entered in the command throughout the page.

At this point, I believe you have a deeper understanding of "how to set the format and color of the SHEEL prompt in Linux". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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