ladybird/Base/usr/share/man/man1/less.md
kleines Filmröllchen 98c0c5e9e6 Help+Base: Add help://man URLs for links between man pages
The URLs of the form `help://man/<section>/<page>` link to another help
page inside the help application. All previous relative page links are
replaced by this new form. This doesn't change any behavior but it looks
much nicer :^)

Note that man doesn't handle these new links, but the previous relative
links didn't work either.
2022-01-11 00:24:57 +01:00

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## Name
`less` - A full-featured terminal pager.
## Synopsis
```**sh
$ cat file | less [-PXem]
$ less [-PXem] [file]
$ cat file | more
$ more [file]
```
## Description
`less` is a terminal pager that allows backwards movement. It is inspired by,
but largely incompatible with
[GNU less](https://www.greenwoodsoftware.com/less/index.html).
## Options
* `-P`, `--prompt`: Set the prompt format string. See [Prompts](#prompts) for more details.
* `-X`, `--no-init`: Don't switch to the xterm alternate buffer on startup.
* `-e`, `--quit-at-eof`: Immediately exit less when the last line of the document is reached.
* `-m`, `--emulate-more`: Apply `-Xe`, set the prompt to `--More--`, and disable
scrollback. This option is automatically applied when `less` is executed as `more`
## Commands
Commands may be preceded by a decimal number `N`. Currently, this feature
does not exist, and no command use `N`.
| Command | Description |
|---------|-------------|
| `q` | Exit less. |
| `j` or `DOWNARROW` or `ENTER` | Go to the next line. |
| `k` or `UPARROW` | Go to the previous line. |
| `SPACE` | Go to the next page. |
## Prompts
`less` accepts a special prompt string with the `-P` option. prompts accept a
variety of format specifiers so that they adapt to `less`'s state.
A `%` followed by a letter will be replaced with the associated variable. If
such a variable does not exist, or currently has no value, it will be replaced
with a `?`.
| Variable | Description |
|----------|-------------|
| `%f` | Replaced with the name of the current file |
| `%l` | Replaced with the current line number |
A `?` followed by a letter acts as an if expression on the associated
condition. `:` then acts as the else, and `.` acts as the end token. for example
if you wanted to print 'true' if you are at the end of the file and 'false'
otherwise, your prompt would be `?etrue:false.`. These expressions are
arbitrarily nestable. If a condition does not exist, then it will always
evaluate it's false branch.
| Condition | Description |
|----------|-------------|
| `?f` | True when reading from a file other than stdin. |
| `?e` | True when at the end of a file. |
A `\\` followed by any character will be replaced with the literal value of the
character. For instance, `\\%l` would render as `%l`.
All other characters are treated normally.
#### Examples
`less`'s current default prompt: `'?f%f :.(line %l)?e (END):.'`
## See Also
* [`more`(1)](help://man/1/more) For a simpler pager that less implements.
* [`man`(1)](help://man/1/man) For serenity's manual pager, that uses less.