Colorize linux programs output

2020-06-03

Colorize linux program output

You can colorize linux bash shell or any linux program like echo, sed, grep and another with this simple steps:

You need type ASCII ESC character before your colorized text
ESC character has to be followed by [
After that you can write one or two numbers separated by ;

First number is one of:
- color-mode: It modifies the style of color NOT text. For example make the color bright or darker.
  - 0 - normal (default)
  - 1 - lighter than normal
  - 2 - darker than normal
- text-mode: This mode is for modifying the style of text NOT color.
  - 3 - italic
  - 4 - underline
  - 5 - blinking (slow)
  - 6 - blinking (fast)
  - 7 - reverse
  - 8 - hide
  - 9 - cross-out
Second number is color-code separated by ; from first number is ANSI color code. eg. 31 for red color, 34 for blue color for 3/4 bit ANSI color code. Color is one of:
- foreground mode - This mode is for colorizing the foreground.
- background mode - This mode is for colorizing the background.

second number - color-code in step 3 is 3/4 bit or 8 bit or 24 bit ANSI color code

Then you have to write m char
You can get back to standard output with ESC[0m

0 is appended if you omit it in step 5 - e.g. you can write ESC[m in bash

ESC - you can type escape character to your console or linux program with some of ASCII code:

Decimal	Octal	Hex	Binary	Value	Description	Carret notation	Escape sequence in bash or C
027	033	1B	0001 1011	ESC	escape	^[	\e

3/4bit ANSI Color

The below table shows a summary of 3/4 bit version of ANSI color.

|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
| color-mode | octal    | hex     | bash  | description      | example (ESC in octal)       | NOTE                                 |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|          0 | \033[0m  | \x1b[0m | \e[0m | reset any affect | echo -e "\033[0m"            | 0m equals to m                       |
|          1 | \033[1m  |         |       | light (= bright) | echo -e "\033[1m####\033[m"  | -                                    |
|          2 | \033[2m  |         |       | dark (= fade)    | echo -e "\033[2m####\033[m"  | -                                    |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|  text-mode | ~        |         |       | ~                | ~                            | ~                                    |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|          3 | \033[3m  |         |       | italic           | echo -e "\033[3m####\033[m"  |                                      |
|          4 | \033[4m  |         |       | underline        | echo -e "\033[4m####\033[m"  |                                      |
|          5 | \033[5m  |         |       | blink (slow)     | echo -e "\033[5m####\033[m"  |                                      |
|          6 | \033[6m  |         |       | blink (fast)     | ?                            | not wildly support                   |
|          7 | \003[7m  |         |       | reverse          | echo -e "\033[7m####\033[m"  | it affects the background/foreground |
|          8 | \033[8m  |         |       | hide             | echo -e "\033[8m####\033[m"  | it affects the background/foreground |
|          9 | \033[9m  |         |       | cross            | echo -e "\033[9m####\033[m"  |                                      |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
| foreground | all below examples are with ommited color/text mode - default is 0                                                  |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         30 | \033[30m |         |       | black            | echo -e "\033[30m####\033[m" |                                      |
|         31 | \033[31m |         |       | red              | echo -e "\033[31m####\033[m" |                                      |
|         32 | \033[32m |         |       | green            | echo -e "\033[32m####\033[m" |                                      |
|         33 | \033[33m |         |       | yellow           | echo -e "\033[33m####\033[m" |                                      |
|         34 | \033[34m |         |       | blue             | echo -e "\033[34m####\033[m" |                                      |
|         35 | \033[35m |         |       | purple           | echo -e "\033[35m####\033[m" | real name: magenta = reddish-purple  |
|         36 | \033[36m |         |       | cyan             | echo -e "\033[36m####\033[m" |                                      |
|         37 | \033[37m |         |       | white            | echo -e "\033[37m####\033[m" |                                      |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         38 | 8/24     |                    This is for special use of 8-bit or 24-bit                                            |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
| background | all below examples are with ommited color/text mode - default is 0                                                  |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         40 | \033[40m |         |       | black            | echo -e "\033[40m####\033[m" |                                      |
|         41 | \033[41m |         |       | red              | echo -e "\033[41m####\033[m" |                                      |
|         42 | \033[42m |         |       | green            | echo -e "\033[42m####\033[m" |                                      |
|         43 | \033[43m |         |       | yellow           | echo -e "\033[43m####\033[m" |                                      |
|         44 | \033[44m |         |       | blue             | echo -e "\033[44m####\033[m" |                                      |
|         45 | \033[45m |         |       | purple           | echo -e "\033[45m####\033[m" | real name: magenta = reddish-purple  |
|         46 | \033[46m |         |       | cyan             | echo -e "\033[46m####\033[m" |                                      |
|         47 | \033[47m |         |       | white            | echo -e "\033[47m####\033[m" |                                      |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         48 | 8/24     |                    This is for special use of 8-bit or 24-bit                                            |                                                                                       
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|

foreground 4-bit summary in a .gif:

3/4 bit foreground bash color output

background 4-bit summary in a .gif

3/4 bit background bash color output

8 bit ANSI Colors

The below table shows a summary of 8 bit version of ANSI color. where $ is color/text mode

|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
| foreground | octal     | hex       | bash    | description      | example                            | NOTE                    |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
|        0-7 | \033[$;38 | \x1b[$;38 | \e[$;38 | standard. normal | echo -e '\033[0;38;1m####\033[m'   | red color               |
|       8-15 |           |           |         | underline        | echo -e '\033[4;38;10m####\033[m'  | light green             |
|     16-231 |           |           |         | reverse          | echo -e '\033[7;38;226m####\033[m' | yellow plus green       |
|    232-255 |           |           |         |                  | echo -e '\033[0;38;242m####\033[m' | from black to white     |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
| background | octal     | hex       | bash    | description      | example                            | NOTE                    |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
|        0-7 |           |           |         | standard. normal | echo -e '\033[0;48;1m####\033[m'   |                         |
|       8-15 |           |           |         |                  | echo -e '\033[0;48;9m####\033[m'   |                         |
|     16-231 |           |           |         |                  | echo -e '\033[0;48;45m####\033[m'  |                         |
|    232-255 |           |           |         |                  | echo -e '\033[0;48;242m####\033[m' | from black to white     |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|

Here is quick test with 8bit color and underline text mode:

~] for code in {0..255}; do echo -e "\e[4;38;${code}m $code: Test"; done

linux bash in color

You can colorize output from echo, printf programs or you can colorize special bash varibles like PS0, PS1, PS2 (prompt) and PS4 also.

Echo and printf use a octal ascii code or C escape sequence for ESC char.

Here is end sequence with octal ESC escape sequence:

end="\033[0m"

Remeber that \033 is ASCII octal escape sequence. Maybe in another program you has to use another escape sequence for ESC char.

Examples

This 4 examples do same colored output:

echo -e "My favorite colors are \033[31m red \033[0m and \033[32m green \033[0m "
echo -e "My favorite colors are \033[0;31m red \033[0m and \033[0;32m green \033[0m"
echo -e "My favorite colors are \e[31m red \e[0m and \e[32m green \e[0m "
echo -e "My favorite colors are \e[0;31m red \e[0m and \e[0;32m green \e[0m"

\033 or \e - escape code for ESC char
[ - ESC character has to be followed by [ (step 2)
color/text mode is ommited - default is 0 or we type exactly 0 color/text mode
31 - color-code from step 3 for 3/4 bit ansi red color, 32 for green color
m - m char from step 4
\033[0m or \e[0m - ending sequence for ESC char

produce:

echo colored output

Example for red/green 3/4 bit ansi color code and underline text mode:

echo -e "My favorite colors are \033[4;31m red \033[0m and \033[4;32m green \033[0m"
echo -e "My favorite colors are \e[4;31m red \e[0m and \e[4;32m green \e[0m"

\033 or \e - escape code for ESC char
[ - ESC character has to be followed by [ (step 2)
4 - color/text mode is number 4 - underline text
31 - color-code from step 3 for 3/4 bit ansi red color, 32 for green color
m - m char from step 4
\033[0m or \e[0m - ending sequence for ESC char

produce:

echo colored output 2

If you are using the echo command, be sure to use the -e flag to allow backslash escapes.

The same is for printf utility:

~] printf "My favorite colors are \033[31m red \033[0m , \033[32m green \033[0m and \033[44m blue \033[0m \n"
~] printf "My favorite colors are \e[31m red \e[0m , \e[32m green \e[0m and \e[44m blue \e[0m \n"

colored printf output

bash exception

If you are going to use these colorized codes in your special bash variables

PS0
PS1
PS2 - prompt
PS4

you should add extra escape characters so that bash can interpret them correctly. You should add [ before any starting ANSI code and add ] after any ending ones.

example:

in regular usage: \033[32mThis is in green\033[0m

for PS0/1/2/4: [\033[32m]This is in green[\033[m]

[ is for start of a sequence of non-printable characters
] is for end of a sequence of non-printable characters

sed colored output

Here is information from sed manual page:

\oxxx

    Produces or matches a character whose octal ASCII value is xxx.

So, for ESC char we have to this escape sequence: \o033

Here is another very important information for & char and \1 through \9 for sed substitution statement:

s/regexp/replacement/

     Attempt to match regexp against the pattern space. If successful, replace that portion matched with replacement. The replacement may contain the special character & to refer to that portion of the pattern space which matched, and the special escapes \1 through \9 to refer to the corresponding matching sub-expressions in the regexp.

examples how colorize sed regex match

~] echo "one two three four five" | sed 's/two/\o033[1;31m&\o033[0m/g'
~] one two three four five

two - regex that we can try match
\o033 - octal ascci escape sequence for ESC char
[1;31m - color-mode 1 - lighter than normal and color-code 31 for red color in 3/4 bit ansi color code
& - special character & to refer to that portion of the regex pattern space which matched 
[0m - end sequence