wiki.bash-hackers.org/commands/builtin/echo.md

# The echo builtin command

## Synopsis

    echo [-neE] [arg ...]

## Description

`echo` outputs it's args to stdout, separated by spaces, followed by a
newline. The return status is always `0`. If the
[shopt](/commands/builtin/shopt) option `xpg_echo` is set, Bash
dynamically determines whether echo should expand escape characters
(listed below) by default based on the current platform. `echo` doesn't
interpret `--` as the end of options, and will simply print this string
if given.

### Options

| Option | Description                                                                                                    |
|:-------|:---------------------------------------------------------------------------------------------------------------|
| `-n`   | The trailing newline is suppressed.                                                                            |
| `-e`   | Interpretation of the following backslash-escaped characters (below) is enabled.                               |
| `-E`   | Disables the interpretation of these escape characters, even on systems where they are interpreted by default. |

### Escape sequences

| Escape       | Description                                                                                                   |
|:-------------|:--------------------------------------------------------------------------------------------------------------|
| `\a`         | alert (bell)                                                                                                  |
| `\b`         | backspace                                                                                                     |
| `\c`         | suppress further output                                                                                       |
| `\e`         |                                                                                                               |
| `\E`         | an escape character                                                                                           |
| `\f`         | form feed                                                                                                     |
| `\n`         | new line                                                                                                      |
| `\r`         | carriage return                                                                                               |
| `\t`         | horizontal tab                                                                                                |
| `\v`         | vertical tab                                                                                                  |
| `\\`         | backslash                                                                                                     |
| `\0nnn`      | the eight-bit character whose value is the octal value nnn (zero to three octal digits)                       |
| `\xHH`       | the eight-bit character whose value is the hexadecimal value HH (one or two hex digits)                       |
| `\uHHHH`     | the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value HHHH (one to four hex digits)      |
| `\UHHHHHHHH` | the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value HHHHHHHH (one to eight hex digits) |

## Examples

## Portability considerations

- `echo` is a portability train wreck. No major shell follows POSIX
  completely, and any shell that attempts to do so should be considered
  horribly broken.
  [SUSv4](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html#tag_20_37)
  specifies that `echo` **shall not** include any options. Further, it
  specifies that the behavior of `-n` as a first argument shall be
  determined by the implementation, unless XSI is followed, in which
  case `-n` is always treated as a string, and backslash escapes are
  interpreted by default. `dash` has the misfeature of following this
  and interpreting escapes by default, but includes a `-n` feature for
  suppressing newlines nevertheless.  
    
  In practice, if you're able to assume a korn-like shell including
  bash, mksh, or zsh, `echo` when used in simple cases is generally
  reliable. For example, in the very common situation in which echo is
  supplied with a single argument and whose output is to have a newline
  appended, using `echo` is considered common practice.

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- **Never use options to `echo`! *Ever*!** Any time you feel tempted to
  use `echo -e`, `-n`, or any other special feature of echo, **use
  [printf](/commands/builtin/printf) instead!** If portability is a
  requirement, you should consider using `printf` *exclusively* and just
  ignore that `echo` even exists. If you must use `echo -e` and refuse
  to use `printf`, it is usually acceptable to use ''echo \$'...' ''if
  targeting only shells that support this special quoting style.

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- `ksh93` has a `print` command, which if coding specifically for
  `ksh93` should be preferred over `echo`.
  [printf](/commands/builtin/printf) still includes most of the
  functionality of both, and should usually be the most preferred
  option.

## See also

- [printf](/commands/builtin/printf)
- <http://cfajohnson.com/shell/cus-faq.html#Q0b>