How can I type ASCII characters like Alt + numpad in Windows? [duplicate]

On Windows, the key combination Alt + 2+ 5+ 5 creates a blank space. How can I achieve this on Ubuntu?

When you type Alt + numbers in Windows, you are actually typing Alt + character's ASCII code.

To achieve the same in Ubuntu, you must type Ctrl + Shift + U, and then type character in Unicode hexadecimal value.

If this shurtcut doesn't work check if your input method is iBus.

Example 1

• Alt + 255 on Windows creates a non-breaking space (ASCII 255)
• This character in Unicode is U+00A0
• On Ubuntu, type it as Ctrl + Shift + U then A0, then Enter

Example 2

• Alt + 173 on Windows creates an inverted exclamation mark (ASCII 173, "¡")
• This character in Unicode is U+00A1
• On Ubuntu, type it as Ctrl + Shift + U then A1, then Enter

The Unicode four-digit hexadecimal number can be found via the Character Map (gucharmap). For just ASCII table type man ascii on a terminal.

Another way — «Compose key»

A compose key, available on some computer keyboards, is a special kind of modifier key designated to signal the software to interpret the following (usually two) keystrokes as a combination in order to produce a character not found directly on the keyboard. For example, striking Compose followed by O and then C can produce the symbol ©, the copyright symbol). wikipedia.org

• ENABLE [Ubuntu 13.04]: System settings... → Keyboard → Layout settings → Options → «Compose key position» and set it, for example, on «Menu» (key between right ALT and CTRL).

• DO: Hold key «Menu» and push «Space» 2 times. Should get 1 non-breaking space: « ».

Here more Linux compose key sequences: hermit.org