---
name: "vis"
section: "1"
platform: "macos"
package: "text_cmds"
version: "199"
release: "macOS 26.5"
platforms: ["linux", "freebsd", "openbsd", "macos"]
url: "https://new.carta.tech/vis"
---

# vis(1)

display non-printable characters in a visual format

## NAME

**vis** – display non-printable characters in a visual format

## SYNOPSIS

**vis** \[**-bcfhlMmNnoSstw**\] \[**-e** *extra*\] \[**-F** *foldwidth*\] \[*file* *...*\]

## DESCRIPTION

**vis** is a filter for converting non-printable characters into a visual representation. It differs from ‘cat -v’ in that the form is unique and invertible. By default, all non-graphic characters except space, tab, and newline are encoded. A detailed description of the various visual formats is given in [vis(3)](/vis/3.md).

The options are as follows:

- **-b**

  Turns off prepending of backslash before up-arrow control sequences and meta characters, and disables the doubling of backslashes. This produces output which is neither invertible or precise, but does represent a minimum of change to the input. It is similar to “cat -v”. (VIS\_NOSLASH)

- **-c**

  Request a format which displays a small subset of the non-printable characters using C-style backslash sequences. (VIS\_CSTYLE)

- **-e** *extra*

  Also encode characters in *extra*, per [svis(3)](/svis/3.md).

- **-F** *foldwidth*

  Causes **vis** to fold output lines to foldwidth columns (default 80), like [fold(1)](/fold/1.md), except that a hidden newline sequence is used, (which is removed when inverting the file back to its original form with [unvis(1)](/unvis/1.md)). If the last character in the encoded file does not end in a newline, a hidden newline sequence is appended to the output. This makes the output usable with various editors and other utilities which typically don't work with partial lines.

- **-f**

  Same as **-F**.

- **-h**

  Encode using the URI encoding from RFC 1808. (VIS\_HTTPSTYLE)

- **-l**

  Mark newlines with the visible sequence ‘\\$’, followed by the newline.

- **-M**

  Encode all shell meta characters (implies **-S**, **-w**, **-g**) (VIS\_META)

- **-m**

  Encode using the MIME Quoted-Printable encoding from RFC 2045. (VIS\_MIMESTYLE)

- **-N**

  Turn on the VIS\_NOLOCALE flag which encodes using the “C” locale, removing any encoding dependencies caused by the current locale settings specified in the environment.

- **-n**

  Turns off any encoding, except for the fact that backslashes are still doubled and hidden newline sequences inserted if **-f** or **-F** is selected. When combined with the **-f** flag, **vis** becomes like an invertible version of the [fold(1)](/fold/1.md) utility. That is, the output can be unfolded by running the output through [unvis(1)](/unvis/1.md).

- **-o**

  Request a format which displays non-printable characters as an octal number, \\ddd. (VIS\_OCTAL)

- **-S**

  Encode shell meta-characters that are non-white space or glob. (VIS\_SHELL)

- **-s**

  Only characters considered unsafe to send to a terminal are encoded. This flag allows backspace, bell, and carriage return in addition to the default space, tab and newline. (VIS\_SAFE)

- **-t**

  Tabs are also encoded. (VIS\_TAB)

- **-w**

  White space (space-tab-newline) is also encoded. (VIS\_WHITE)

## MULTIBYTE CHARACTER SUPPORT

**vis** supports multibyte character input. The encoding conversion is influenced by the setting of the LC\_CTYPE environment variable which defines the set of characters that can be copied without encoding.

When 8-bit data is present in the input, LC\_CTYPE must be set to the correct locale or to the C locale. If the locales of the data and the conversion are mismatched, multibyte character recognition may fail and encoding will be performed byte-by-byte instead.

## ENVIRONMENT

- LC\_CTYPE

  Specify the locale of the input data. Set to C if the input data locale is unknown.

## EXAMPLES

Visualize characters encoding white spaces and tabs:

```
$ echo -e "\x10\n\t" | vis -w -t
\^P\012\011\012
```

Same as above but using \`\\$' for newline followed by an actual newline:

```
$ echo -e "\x10\n\t" | vis -w -t -l
\^P\$
\011\$
```

Visualize string using URI encoding:

```
$ echo http://www.freebsd.org | vis -h
http%3a%2f%2fwww.freebsd.org%0a
```

## SEE ALSO

[unvis(1)](/unvis/1.md), [svis(3)](/svis/3.md), [vis(3)](/vis/3.md)

## HISTORY

The **vis** command appears in 4.4BSD. Multibyte character support was added in NetBSD 7.0 and FreeBSD 9.2.