NAME

mview - Internal file viewer of M-Commander.

SYNOPSIS

mview [-bcCdfhstVx?] file

DESCRIPTION

mview is a link to mcommander, the main M-Commander executable. Executing M-Commander under this name requests staring the internal viewer and opening the file specified on the command line.

OPTIONS

-b

Force black and white display.

-c

Force color mode on terminals where mview defaults to black and white.

-d

Disable mouse support.

-f

Display the compiled-in search paths for M-Commander files.

-S arg, --skin=arg

Specify a name of skin in the command line. See the Skins section in mcommander(1) for more information.

-t

Used only if the code was compiled with S-Lang and terminfo: it makes M-Commander use the value of the TERMCAP variable for the terminal information instead of the information on the system wide terminal database

-V

Displays the version of the program.

-x

Forces xterm mode. Used when running on xterm-capable terminals (two screen modes, and able to send mouse escape sequences).

Internal File Viewer

The internal file viewer provides three display modes: ASCII, hex and structured (tree). To toggle between ASCII and hex, use the F4 key. To toggle the structured mode, use Alt-s or t. Inside the ASCII mode F9 steps through three renderings of the same bytes: plain text, the ANSI colors the file carries, and a terminal emulator fed with the file.

The viewer will try to use the best method provided by your system or the file type to display the information. In the nroff mode, which the extensions file turns on for manual pages, the overstrike sequences of a preformatted page are displayed bold and underlined instead of being printed as they stand.

In ASCII mode the arrow keys move the view until the reading cursor is turned on. Enter turns it on, and off again; a click and the keys that mark turn it on as well. With the cursor on, the arrow keys walk the text and the Shift-arrow, Shift-Home, Shift-End, Shift-PageUp and Shift-PageDown keys mark it.

Drag with the left mouse button to select text. A double click selects a word and a triple click selects a visual line. A single click only places the cursor on a character; it marks the point the shifted keys extend the selection from. When the text scrolls (PageDown, the mouse wheel), the cursor stays on the screen in the same row and column. Press Ctrl-Insert or Enter to copy the selection to the clipfile and then to the external clipboard; C-u clears the selection and turns the cursor off, and so does copying. Enter acts as Down where there is no cursor to turn on, in hex and tree modes. Any cursor movement without Shift drops the selection and keeps the cursor. The copied value is the displayed text: ANSI and nroff formatting is removed, tabs are expanded to spaces, and in filter mode only the visible lines are copied.

Since the left button selects text, scrolling by clicking in the upper or lower third of the view (see mouse_move_pages in the [Viewer] section) is done with the right or middle mouse button in ASCII mode. The mouse wheel scrolls two lines at a time, in every mode.

F6 filters the view the way grep does: only the lines that match a pattern are shown, and the status line counts them. The dialog takes the pattern and the same search type, case and whole word settings the search has; the Check button lists the lines the pattern picks before the filter is applied, and F1 there opens the quick reference of regular expressions. An empty pattern clears the filter, and while nothing matches the view says so and stays where it is. The keys ] and [ walk the matches, and C-t turns the follow mode on, where the view stays on the last match while the file grows, the way tail -f does. A large file is read in the background, and the status line says so while it is being read.

When in hex mode, the search function accepts text in quotes and constant numbers. Text in quotes is matched exactly after removing the quotes. Each number matches one byte. You can mix quoted text with constants like this:

"String" 34 0xBB 012 "more text"

Numbers are always interpreted in hex. In the example above, "34" is interpreted as 0x34. The prefix "0x" isn't really needed: we could type "BB" instead of "0xBB". And "012" is interpreted as 0x12, not as an octal number.

The structured mode renders JSON, YAML and XML files as an expandable tree; an HTML file is read by the same parser as XML. The format is taken from the name of the file, from what the file command says about it, and from the text itself. Press Alt-s (or t) on a supported file to enter it; if the file cannot be parsed, or it is larger than the tree view takes, a diagnostic is shown and the viewer stays in ASCII mode. The tree works on local files only, and entering it puts the line filter and the terminal mode aside. YAML is handled by a built-in parser that covers the commonly used subset (block mappings and sequences, block scalars, quoted scalars, anchors and aliases). Aliases are expanded by copying; a cyclic alias, or expansion beyond an internal node budget, is displayed as a *name reference instead of a copy. Tags and flow collections ([] and {}) are not parsed and appear as plain text values; documents outside the subset (multi-line plain scalars, tab characters in indentation) are reported and shown as plain text. Inside the tree F4, Alt-s and t return to the ASCII mode. The status line shows the content type and the jq-style path of the current node (for example .spec.containers[0].image). A click moves the cursor of the tree, and a click on the row the cursor is on expands or collapses that node. The mode also works in the quick view panel (C-x q), where the tree follows the panel cursor. With the structured_auto option of the [Viewer] section enabled supported files open in the tree right away. Keys available inside the tree:

Enter        expand/collapse the current node; on a leaf show


             the full value
Right/Left   expand / collapse (on a collapsed node Left jumps


             to the parent)
*            expand the current subtree recursively
+ / -        expand / collapse the whole tree
1 .. 9       expand the whole document to the given depth
Alt-Enter    copy the path of the current node to the clipboard
F7, /        search the whole document, including collapsed


             nodes; the path to a match is expanded
F17, n       continue the search
F6           filter the tree by a pattern
] / [        go to the next / previous match of the filter

The filter (F6) takes the pattern in the same dialog as the one of the ASCII mode, with the same type, case and whole-word settings, and keeps only the nodes whose key or value matches it. The path down to every match stays visible, and so does what is inside a match, so a matched node can still be opened and browsed. The status line counts the matches; ] and [ walk them. An empty pattern clears the filter, and so does leaving the tree. A node matches on the text its row shows, so a long value is matched only up to the length the tree keeps for the preview (160 characters).

The keys that move in the text move in the tree as well: the arrows and h, j, k and l, the page keys, and the ones that go to the beginning and the end. Alt-e picks the charset and C-o shows the command screen, as they do in the text.

Here is a listing of the actions associated with each key that the M-Commander handles in the internal file viewer.

F1

Invoke the built-in hypertext help viewer.

F2

Toggle the wrap mode. In hex mode it switches to editing the bytes and back; F6 writes the changes to the file.

F4

Toggle the hex mode.

Alt-s, t

Toggle the structured (tree) mode for JSON, YAML and XML files.

F14

Show the file in the structure viewer, the mcstruct plugin, at the byte the cursor is on. It works on local files only.

F6

Filter the view by a pattern. In hex mode, save the changes made to the bytes.

C-t

Toggle the follow mode of the filter.

], [

Go to the next or the previous match of the filter.

F5

Goto. The dialog takes a line number, a percentage of the size of the file, or an offset written in decimal or in hexadecimal, whichever of the four is chosen in it.

F7, /, ?

Start search. These keys call the dialog window that allows you to set up the search options. If key is ? the "Backwards" option is on.

C-s

Continue forward search.

C-r

Continue reverse search.

F17, n

Continue search in the chosen direction.

N

Temporary change the search direction: backwards if forward search is chosen, and vice versa.

Shift-F8

Toggle syntax highlighting: the text is colored by the syntax rules, the same ones and the same way the internal editor uses. Above 4 MB a file gets the line-local rules instead, which color numbers, quoted strings and punctuation without having to read everything above the line being shown. The text keeps its own colors while the ANSI mode, the hex mode or the terminal mode is on, and the syntax rules step aside there.

Shift-F9

Toggle interpretation of ANSI color escape sequences found in the text.

F8

Toggle Raw/Parsed mode: This will show the file as found on disk or if a processing filter has been specified in the extensions.ini file, then the output from the filter. Current mode is always the other than written on the button label, since on the button is the mode which you enter by that key.

F9

Step through the ways the text is shown: plain, then with the ANSI colors of the file, then the terminal mode, where the file is fed to a terminal emulator and the screen it draws is what the viewer shows. The button label names the mode the key leads to, not the one the viewer is in. The terminal mode is built from the stream and not from the lines of the file, so the wrapping, the goto, the filter and the search have nothing to work on there, and the button bar says so.

F3, F10, Esc, q

Exit the internal file viewer.

PageDown, space, f, C-v

Scroll one page forward.

PageUp, b, Alt-v, Backspace

Scroll one page backward.

d, u

Scroll half a page forward or backward.

C-a, C-e

Move to the beginning or the end of the line.

Home, C-Home, C-PageUp, g

Go to the beginning of the file.

End, C-End, C-PageDown, G

Go to the end of the file.

Down, Up

Move the text cursor one row down or up; on the edge of the view the text scrolls by one line. In hex mode they scroll one line.

Left, Right

Move the text cursor by one displayed character; at the end of the row it goes on to the next one. In hex mode they move the hex cursor.

h, j, k, l

Move left, down, up and right, as the arrow keys do. The keys Insert and Delete, C-p and C-n, and y and e move one row up and down as well.

Tab

In hex mode, switch between the hex column and the text column.

C-Left, C-Right

Move the text cursor by eight displayed characters. With the cursor off and the lines not wrapped, they scroll the view ten columns sideways.

Shift-Left, Shift-Right, Shift-Up, Shift-Down

Extend the text selection by one displayed character or row.

Shift-Home, Shift-End

Extend the text selection to the start or end of the visual row.

Shift-PageUp, Shift-PageDown

Extend the text selection to the first or last visible row.

Ctrl-Insert, Enter

Copy selected text to the clipfile and external clipboard. With no selection, Enter acts as Down.

C-u

Clear the text selection.

C-l

Refresh the screen.

C-o

Toggle the terminal and show the command screen.

[n] m

Set the mark n.

[n] r

Jump to the mark n.

C-f

Jump to the next file. Not in the quick view panel, which follows the cursor of the other panel.

C-b

Jump to the previous file. Not in the quick view panel either.

Alt-r

Step the ruler through the top of the view, the bottom of it, and off.

Alt-Shift-e

Open the list of the files viewed before and show the one that is chosen.

Alt-e

to change charset of displayed text may use Alt-e (M-e). Recoding is made from selected codepage into system codepage. To cancel the recoding you may select "<No translation>" in charset selection dialog.

It's possible to instruct the file viewer how to display a file, look at the Edit Extension File section

Viewer options

The options of the internal viewer that hold for every file it opens.

Wrap long lines. If enabled, a line wider than the screen is continued on the next screen line; otherwise it is cut and the view scrolls sideways. Enabled by default.

Syntax highlighting. If enabled, the viewer colors the text by the syntax rules of the editor. A file opened in a mode that brings its own colors, such as a man page or rendered Markdown, keeps those colors. Disabled by default.

Mouse page scrolling. How far a click in the upper or the lower third of the view scrolls: half a screen when enabled, one line when disabled. The mouse wheel is not affected, it always scrolls two lines. Enabled by default.

Remember file position. If enabled, the viewer opens a file at the place it was left the last time. Disabled by default.

Tree view of JSON, YAML and XML. If enabled, a file of one of these formats opens as a tree that can be folded, instead of plain text. The same view is always available with the key that switches the display mode. Disabled by default.

End of file marker. The text printed after the last line of the file. Empty by default, which prints nothing.

Redraws to skip at most. While a file is still being read, the viewer skips redraws to keep up with the data. This is how many it may skip in a row before it draws anyway. The default is 10.

Tree view file limit, MB. The largest file the tree mode parses. A larger one is refused before it is read. 64 by default.

Tree view node limit. The largest tree the mode builds, counted in nodes. A dense document, such as XML of small tags, meets this limit before the size one. 10000000 by default.

FILES

/usr/share/mcommander/help/mcommander.md

The help file for the program.

/usr/share/mcommander/mc.ini

The default system-wide setup for M-Commander, used only if the user's own ~/.config/mc6/ini file is missing.

/usr/share/mcommander/defaults.ini

Global settings for M-Commander. Settings in this file affect all users, whether they have ~/.config/mc6/ini or not.

~/.config/mc6/ini

User's own setup. If this file is present, the setup is loaded from here instead of the system-wide startup file.

LICENSE

This program is distributed under the terms of the GNU General Public License as published by the Free Software Foundation. See the built-in help of M-Commander for details on the License and the lack of warranty.

AVAILABILITY

The latest version of this program can be found at https://github.com/blue-panels/mcommander/releases .

SEE ALSO

mcommander(1), mcedit6(1)

BUGS

Bugs should be reported to https://github.com/blue-panels/mcommander/issues .