echo Options and Escape Sequences

echo accepts a number of arguments (see Table A-11).

Table A-11. echo options

Options

Function

-e

Turns on the interpretation of backslash-escaped characters

-E

Turns off the interpretation of backslash-escaped characters on systems where this mode is the default

-n

Omits the final newline (same as the \c escape sequence)

echo accepts a number of escape sequences that start with a backslash.

These sequences in Table A-12 exhibit fairly predictable behavior, except for \f, which on some displays causes a screen clear while on others it causes a line feed, and it ejects the page on most printers. \v is somewhat obsolete; it usually causes a line feed.

Table A-12. echo escape sequences

Sequence

Character printed

\a

Alert or Ctrl-G (bell)

\b

Backspace or Ctrl-H

\c

Omit final newline

\e

Escape character (same as \E)

\E

Escape character

\f

Formfeed or Ctrl-L

\n

Newline (not at end of command) or Ctrl-J

\r

Return (Enter) or Ctrl-M

\t

Tab or Ctrl-I

\v

Vertical Tab or Ctrl-K

\n nnn

The eight-bit character whose value is the octal (base-8) value nnn where nnn is 1 to 3 digits

\0 nnn

The eight-bit character whose value is the octal (base-8) value nnn where nnn is 0 to 3 digits

\xHH

The eight-bit character whose value is the hexadecimal (base-16) value HH (one or two digits)

\\

Single backslash

The \n, \0, and \x sequences are even more device-dependent and can be used for complex I/O, such as cursor control and special graphics characters.

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