col - Filters text containing linefeeds
col [-bfhpx] [-l number]
command reads from standard input and writes
to standard output.
Interfaces documented on this reference page conform to industry standards as follows:
col: XPG4, XPG4-UNIX
Refer to the
reference page for more information
about industry standards and associated tags.
Assumes that the output device in use is not capable of backspacing.
In this case, if two or more characters are to be displayed in the same position,
only the last one that is read is displayed in the output. This function
is useful for converting
output to produce readable
results on terminals or printers that do not support underlining or overstriking
Suppresses the default treatment of half-line motions in the
does not emit half-line motions on
output, although it does accept them in its input. With this option, output
may contain forward half-linefeeds (<ESC-9>), but not
reverse linefeeds (<ESC-7>
[Compaq] Compresses spaces into tabs. This is the default.
[Compaq] Buffers at least
lines in memory. By default, 128 lines are buffered.
Displays unknown escape sequences as characters, subject to
overprinting from reverse line motions. Normally,
ignores them. You should be fully aware of the textual position of escape
sequences before you use this option.
Outputs multiple spaces instead of tabs.
The col command performs the line overlays implied by reverse linefeeds (ASCII <ESC-7>), and by forward and reverse half-linefeeds (ASCII <ESC-9> and ASCII <ESC-8>). It also replaces white-space characters with tabs where possible.
[Compaq] The col command is particularly useful for filtering multicolumn output made by the nroff and tbl commands.
The col command assumes that the ASCII control characters SO (\017) and SI (\016) begin and end text in an alternate character set. The col command remembers the character set each input character belongs to, and on output generates SI and SO characters as appropriate to ensure that each character is printed in the correct character set.
On input, the col command accepts only the control characters for the <Space>, <Backspace>, <Tab>, and <Return> keys; the newline character; the SI, SO, and VT control characters; and <ESC-7>, <ESC-8>, or <ESC-9>. The VT control character (\013) is an alternate form of full reverse linefeed included for compatibility with some earlier programs of this type. The col command discards all other nonprinting characters.
[Compaq] If the input attempts to back up to the last flushed line,
displays a warning message.
Depending on the printer, using the
may increase printing time.
Local vertical motion that causes a backwards move over the
first line of input is ignored. The first line of input may not have any
This command is marked for possible future withdrawal from
the XPG4-UNIX standard. It may be replaced by features designed for
greater internationalization features.
The following exit values are returned:
An error occurred.
The following environment variables affect the execution of
Provides a default value for the internationalization variables
that are unset or null. If
is unset or null, the corresponding value from the default locale is used.
If any of the internationalization variables contain an invalid setting, the
utility behaves as if none of the variables had been defined.
If set to a non-empty string value, overrides the values of
all the other internationalization variables.
Determines the locale for the interpretation of sequences
of bytes of text data as characters (for example, single-byte as opposed to
multibyte characters in arguments).
Determines the locale for the format and contents of diagnostic
messages written to standard error.
Determines the location of message catalogues for the processing
Commands: deroff(1), neqn(1), nroff(1), tbl(1)