less(1)
NAME
less, more - opposite of more
SYNOPSIS
less -?
less [-[+]aBcCdeEfHimMnNqQrsSuUw]
[-b bufs] [-h lines] [-j line] [-k keyfile]
[-{oO} logfile] [-p pattern] [-P prompt] [-t tag]
[-T tagfile] [-x tab] [-y lines] [-[z] lines]
[+[+]cmd] [filename]...
DESCRIPTION
Less is a program similar to more (1), but which allows backward movement
in the file as well as forward movement. Also, less does not have to
read the entire input file before starting, so with large input files it
starts up faster than text editors like vi (1). Less uses termcap (or
terminfo on some systems), so it can run on a variety of terminals.
There is even limited support for hardcopy terminals. (On a hardcopy
terminal, lines which should be printed at the top of the screen are
prefixed with an up-arrow.)
Commands are based on both more and vi. Commands may be preceded by a
decimal number, called N in the descriptions below. The number is used
by some commands, as indicated.
COMMANDS
In the following descriptions, ^X means control-X. ESC stands for the
ESCAPE key; for example ESC-v means the two character sequence "ESCAPE",
then "v".
h or H
Help: display a summary of these commands. If you forget all the
other commands, remember this one.
SPACE or ^V or f or ^F
Scroll forward N lines, default one window (see option -z below).
If N is more than the screen size, only the final screenful is
displayed. Warning: some systems use ^V as a special literalization
character.
z Like SPACE, but if N is specified, it becomes the new window size.
RETURN or ^N or e or ^E or j or ^J
Scroll forward N lines, default 1. The entire N lines are
displayed, even if N is more than the screen size.
d or ^D
Scroll forward N lines, default one half of the screen size. If N
is specified, it becomes the new default for subsequent d and u
commands.
b or ^B or ESC-v
Scroll backward N lines, default one window (see option -z below).
If N is more than the screen size, only the final screenful is
displayed.
w Like ESC-v, but if N is specified, it becomes the new window size.
y or ^Y or ^P or k or ^K
Scroll backward N lines, default 1. The entire N lines are
displayed, even if N is more than the screen size. Warning: some
systems use ^Y as a special job control character.
u or ^U
Scroll backward N lines, default one half of the screen size. If N
is specified, it becomes the new default for subsequent d and u
commands.
r or ^R or ^L
Repaint the screen.
R Repaint the screen, discarding any buffered input. Useful if the
file is changing while it is being viewed.
F Scroll forward, and keep trying to read when the end of file is
reached. Normally this command would be used when already at the
end of the file. It is a way to monitor the tail of a file which is
growing while it is being viewed. (The behavior is similar to the
"tail -f" command.)
g or < or ESC-<
Go to line N in the file, default 1 (beginning of file). (Warning:
this may be slow if N is large.)
G or > or ESC->
Go to line N in the file, default the end of the file. (Warning:
this may be slow if N is large, or if N is not specified and
standard input, rather than a file, is being read.)
p or %
Go to a position N percent into the file. N should be between 0 and
100. (This works if standard input is being read, but only if less
has already read to the end of the file. It is always fast, but not
always useful.)
{ If a left curly bracket appears in the top line displayed on the
screen, the { command will go to the matching right curly bracket.
The matching right curly bracket is positioned on the bottom line of
the screen. If there is more than one left curly bracket on the top
line, a number N may be used to specify the N-th bracket on the
line.
} If a right curly bracket appears in the bottom line displayed on the
screen, the } command will go to the matching left curly bracket.
The matching left curly bracket is positioned on the top line of the
screen. If there is more than one right curly bracket on the top
line, a number N may be used to specify the N-th bracket on the
line.
( Like {, but applies to parentheses rather than curly brackets.
) Like }, but applies to parentheses rather than curly brackets.
[ Like {, but applies to square brackets rather than curly brackets.
] Like }, but applies to square brackets rather than curly brackets.
ESC-^F
Followed by two characters, acts like {, but uses the two characters
as open and close brackets, respectively. For example, "ESC ^F < >"
could be used to go forward to the > which matches the < in the top
displayed line.
ESC-^B
Followed by two characters, acts like }, but uses the two characters
as open and close brackets, respectively. For example, "ESC ^B < >"
could be used to go backward to the < which matches the > in the
bottom displayed line.
m Followed by any lowercase letter, marks the current position with
that letter.
' (Single quote.) Followed by any lowercase letter, returns to the
position which was previously marked with that letter. Followed by
another single quote, returns to the position at which the last
"large" movement command was executed. Followed by a ^ or $, jumps
to the beginning or end of the file respectively. Marks are
preserved when a new file is examined, so the ' command can be used
to switch between input files.
^X^X Same as single quote.
/pattern
Search forward in the file for the N-th line containing the pattern.
N defaults to 1. The pattern is a regular expression, as recognized
by ed. The search starts at the second line displayed (but see the
-a and -j options, which change this).
Certain characters are special if entered at the beginning of the
pattern; they modify the type of search rather than become part of
the pattern:
! Search for lines which do NOT match the pattern.
* Search multiple files. That is, if the search reaches the end of
the current file without finding a match, the search continues in
the next file in the command line list.
@ Begin the search at the first line of the first file in the command
line list, regardless of what is currently displayed on the screen
or the settings of the -a or -j options.
?pattern
Search backward in the file for the N-th line containing the
pattern. The search starts at the line immediately before the top
line displayed.
Certain characters are special as in the / command:
! Search for lines which do NOT match the pattern.
* Search multiple files. That is, if the search reaches the beginning
of the current file without finding a match, the search continues in
the previous file in the command line list.
@ Begin the search at the last line of the last file in the command
line list, regardless of what is currently displayed on the screen
or the settings of the -a or -j options.
ESC-/pattern
Same as "/*".
ESC-?pattern
Same as "?*".
n Repeat previous search, for N-th line containing the last pattern.
If the previous search was modified by !, the search is made for the
N-th line NOT containing the pattern. If the previous search was
modified by *, the search continues in the next (or previous) file
if not satisfied in the current file. There is no effect if the
previous search was modified by @.
N Repeat previous search, but in the reverse direction.
ESC-n
Repeat previous search, but crossing file boundaries. The effect is
as if the previous search were modified by *.
ESC-N
Repeat previous search, but in the reverse direction and crossing
file boundaries.
:e [filename]
Examine a new file. If the filename is missing, the "current" file
(see the :n and :p commands below) from the list of files in the
command line is re-examined. A percent sign (%) in the filename is
replaced by the name of the current file. A pound sign (#) is
replaced by the name of the previously examined file. The filename
is inserted into the command line list of files so that it can be
seen by subsequent :n and :p commands. If the filename consists of
several files, they are all inserted into the list of files and the
first one is examined.
^X^V or E
Same as :e. Warning: some systems use ^V as a special
literalization character.
:n Examine the next file (from the list of files given in the command
line). If a number N is specified, the N-th next file is examined.
:p Examine the previous file in the command line list. If a number N
is specified, the N-th previous file is examined.
:x Examine the first file in the command line list. If a number N is
specified, the N-th file in the list is examined.
= or ^G or :f
Prints some information about the file being viewed, including its
name and the line number and byte offset of the bottom line being
displayed. If possible, it also prints the length of the file, the
number of lines in the file and the percent of the file above the
last displayed line.
- Followed by one of the command line option letters (see below), this
will change the setting of that option and print a message
describing the new setting. If the option letter has a numeric
value (such as -b or -h), or a string value (such as -P or -t), a
new value may be entered after the option letter. If no new value
is entered, a message describing the current setting is printed and
nothing is changed.
-+ Followed by one of the command line option letters (see below), this
will reset the option to its default setting and print a message
describing the new setting. (The "-+X" command does the same thing
as "-+X" on the command line.) This does not work for string-valued
options.
-- Followed by one of the command line option letters (see below), this
will reset the option to the "opposite" of its default setting and
print a message describing the new setting. (The "--X" command does
the same thing as "-X" on the command line.) This does not work for
numeric or string-valued options.
_ (Underscore.) Followed by one of the command line option letters
(see below), this will print a message describing the current
setting of that option. The setting of the option is not changed.
+cmd Causes the specified cmd to be executed each time a new file is
examined. For example, +G causes less to initially display each
file starting at the end rather than the beginning.
V Prints the version number of less being run.
q or :q or :Q or ZZ or ESC ESC
Exits less.
The following three commands may or may not be valid, depending on your
particular installation.
v Invokes an editor to edit the current file being viewed. The editor
is taken from the environment variable EDITOR, or defaults to "vi".
See also the discussion of LESSEDIT under the section on PROMPTS
below.
! shell-command
Invokes a shell to run the shell-command given. A percent sign (%)
in the command is replaced by the name of the current file. A pound
sign (#) is replaced by the name of the previously examined file.
"!!" repeats the last shell command. "!" with no shell command
simply invokes a shell. In all cases, the shell is taken from the
environment variable SHELL, or defaults to "sh".
| <m> shell-command
<m> represents any mark letter. Pipes a section of the input file
to the given shell command. The section of the file to be piped is
between the first line on the current screen and the position marked
by the letter. <m> may also be ^ or $ to indicate beginning or end
of file respectively. If <m> is . or newline, the current screen is
piped.
OPTIONS
Command line options are described below. Most options may be changed
while less is running, via the "-" command.
Options are also taken from the environment variable "LESS". For
example, to avoid typing "less -options ..." each time less is invoked,
you might tell csh:
setenv LESS "-options"
or if you use sh:
LESS="-options"; export LESS
The environment variable is parsed before the command line, so command
line options override the LESS environment variable. If an option
appears in the LESS variable, it can be reset to its default on the
command line by beginning the command line option with "-+".
A dollar sign ($) may be used to signal the end of an option string.
This is important only for options like -P which take a following string.
-? This option displays a summary of the commands accepted by less (the
same as the h command). If this option is given, all other options
are ignored, and less exits after the help screen is viewed.
(Depending on how your shell interprets the question mark, it may be
necessary to quote the question mark, thus: "-\?".)
-a Causes searches to start after the last line displayed on the
screen, thus skipping all lines displayed on the screen. By
default, searches start at the second line on the screen (or after
the last found line; see the -j option).
-bn Causes less to use a non-standard number of buffers. Buffers are
1K, and by default 10 buffers are used (except if data in coming
from standard input; see the -B option). The number n specifies a
different number of buffers to use.
-B Disables automatic allocation of buffers, so that only the default
number of buffers are used. If more data is read than will fit in
the buffers, the oldest data is discarded. By default, when data is
coming from standard input, buffers are allocated automatically as
needed to avoid loss of data.
-c Causes full screen repaints to be painted from the top line down.
By default, full screen repaints are done by scrolling from the
bottom of the screen.
-C The -C option is like -c, but the screen is cleared before it is
repainted.
-d The -d option suppresses the error message normally displayed if the
terminal is dumb; that is, lacks some important capability, such as
the ability to clear the screen or scroll backward. The -d option
does not otherwise change the behavior of less on a dumb terminal).
-e Causes less to automatically exit the second time it reaches end-of-
file. By default, the only way to exit less is via the "q" command.
-E Causes less to automatically exit the first time it reaches end-of-
file.
-f Forces non-regular files to be opened. (A non-regular file is a
directory or a device special file.) Also suppresses the warning
message when a binary file is opened. By default, less will refuse
to open non-regular files.
-hn Specifies a maximum number of lines to scroll backward. If it is
necessary to scroll backward more than n lines, the screen is
repainted in a forward direction instead. (If the terminal does not
have the ability to scroll backward, -h0 is implied.)
-i Causes searches to ignore case; that is, uppercase and lowercase are
considered identical. This option is ignored if any uppercase
letters appear in the search pattern.
-jn Specifies a line on the screen where "target" lines are to be
positioned. Target lines are the object of text searches, tag
searches, jumps to a line number, jumps to a file percentage, and
jumps to a marked position. The screen line is specified by a
number: the top line on the screen is 1, the next is 2, and so on.
The number may be negative to specify a line relative to the bottom
of the screen: the bottom line on the screen is -1, the second to
the bottom is -2, and so on. If the -j option is used, searches
begin at the line immediately after the target line. For example,
if "-j4" is used, the target line is the fourth line on the screen,
so searches begin at the fifth line on the screen.
-kfilename
Causes less to open and interpret the named file as a lesskey (1)
file. Multiple -k options may be specified. If a file called .less
exists in the user's home directory, this file is also used as a
lesskey file.
-m Causes less to prompt verbosely (like more), with the percent into
the file. By default, less prompts with a colon.
-M Causes less to prompt even more verbosely than more.
-n Suppresses line numbers. The default (to use line numbers) may
cause less to run more slowly in some cases, especially with a very
large input file. Suppressing line numbers with the -n flag will
avoid this problem. Using line numbers means: the line number will
be displayed in the verbose prompt and in the = command, and the v
command will pass the current line number to the editor (see also
the discussion of LESSEDIT in PROMPTS below).
-N Causes a line number to be displayed at the beginning of each line
in the display.
-ofilename
Causes less to copy its input to the named file as it is being
viewed. This applies only when the input file is a pipe, not an
ordinary file. If the file already exists, less will ask for
confirmation before overwriting it.
-Ofilename
The -O option is like -o, but it will overwrite an existing file
without asking for confirmation.
If no log file has been specified, the -o and -O options can be used
from within less to specify a log file. Without a file name, they
will simply report the name of the log file. The "s" command is
equivalent to specifying -o from within less.
-ppattern
The -p option on the command line is equivalent to specifying
+/pattern; that is, it tells less to start at the first occurence of
pattern in the file.
-Pprompt
Provides a way to tailor the three prompt styles to your own
preference. This option would normally be put in the LESS
environment variable, rather than being typed in with each less
command. Such an option must either be the last option in the LESS
variable, or be terminated by a dollar sign. -P followed by a
string changes the default (short) prompt to that string. -Pm
changes the medium (-m) prompt to the string, and -PM changes the
long (-M) prompt. Also, -P= changes the message printed by the =
command to the given string. All prompt strings consist of a
sequence of letters and special escape sequences. See the section
on PROMPTS for more details.
-q Causes moderately "quiet" operation: the terminal bell is not rung
if an attempt is made to scroll past the end of the file or before
the beginning of the file. If the terminal has a "visual bell", it
is used instead. The bell will be rung on certain other errors,
such as typing an invalid character. The default is to ring the
terminal bell in all such cases.
-Q Causes totally "quiet" operation: the terminal bell is never rung.
-r Causes "raw" control characters to be displayed. The default is to
display control characters using the caret notation; for example, a
control-A (octal 001) is displayed as "^A". Warning: when the -r
flag is used, less cannot keep track of the actual appearance of the
screen (since this depends on how the screen responds to each type
of control character). Thus, various display problems may result,
such as long lines being split in the wrong place.
-s Causes consecutive blank lines to be squeezed into a single blank
line. This is useful when viewing nroff output.
-S Causes lines longer than the screen width to be chopped rather than
folded. That is, the remainder of a long line is simply discarded.
The default is to fold long lines; that is, display the remainder on
the next line.
-ttag
The -t option, followed immediately by a TAG, will edit the file
containing that tag. For this to work, there must be a file called
"tags" in the current directory, which was previously built by the
ctags (1) command. This option may also be specified from within
less (using the - command) as a way of examining a new file. The
command ":t" is equivalent to specifying -t from within less.
-Ttagsfile
Specifies a tags file to be used instead of "tags".
-u Causes backspaces and carriage returns to be treated as printable
characters; that is, they are sent to the terminal when they appear
in the input.
-U Causes backspaces and carriage returns to be treated as control
characters; that is, they are handled as specified by the -r option.
By default, if neither -u nor -U is given, backspaces which appear
adjacent to an underscore character are treated specially: the
underlined text is displayed using the terminal's hardware
underlining capability. Also, backspaces which appear between two
identical characters are treated specially: the overstruck text is
printed using the terminal's hardware boldface capability. Other
backspaces are deleted, along with the preceding character.
Carriage returns immediately followed by a newline are deleted.
Other carriage returns are handled as specified by the -r option.
-w Causes blank lines to be used to represent lines past the end of the
file. By default, a tilde character is used.
-xn Sets tab stops every n positions. The default for n is 8.
-yn Specifies a maximum number of lines to scroll forward. If it is
necessary to scroll forward more than n lines, the screen is
repainted instead. The -c or -C option may be used to repaint from
the top of the screen if desired. By default, any forward movement
causes scrolling.
-[z]n
Changes the default scrolling window size to n lines. The default
is one screenful. The z and w commands can also be used to change
the window size. The "z" may be omitted, as in "-n" for
compatibility with more.
+ If a command line option begins with +, the remainder of that option
is taken to be an initial command to less. For example, +G tells
less to start at the end of the file rather than the beginning, and
+/xyz tells it to start at the first occurrence of "xyz" in the
file. As a special case, +<number> acts like +<number>g; that is,
it starts the display at the specified line number (however, see the
caveat under the "g" command above). If the option starts with ++,
the initial command applies to every file being viewed, not just the
first one. The + command described previously may also be used to
set (or change) an initial command for every file.
KEY BINDINGS
You may define your own less commands by using the program lesskey (1) to
create a file called ".less" in your home directory. This file specifies
a set of command keys and an action associated with each key. See the
lesskey manual page for more details.
NATIONAL CHARACTER SETS
There are three types of characters in the input file:
normal characters
can be displayed directly to the screen.
control characters
should not be displayed directly, but are expected to be found in
ordinary text files (such as backspace and tab).
binary characters
cannot be displayed directly and are not expected to be found in
text files.
By default, less uses the ASCII character set. In the ASCII character
set, characters with values between 128 and 255 are treated as binary.
The LESSCHARSET environment variable may be used to select another
character set. If it is set to the value "latin1", the ISO 8859/1
character set is assumed. Latin-1 is the same as ASCII, except
characters between 128 and 255 are treated as normal characters. The
only valid values for LESSCHARSET currently are "ascii" and "latin1".
In special cases, it may be desired to tailor less to use a character set
other than the ones definable by LESSCHARSET. In this case, the
environment variable LESSCHARDEF can be used to define a character set.
It should be set to a string where each character in the string
represents one character in the character set. The character "." is used
for a normal character, "c" for control, and "b" for binary. A decimal
number may be used for repetition. For example, "bccc4b." would mean
character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are binary,
and 8 is normal. All characters after the last are taken to be the same
as the last, so characters 9 through 255 would be normal. (This is an
example, and does not necessarily represent any real character set.)
Setting LESSCHARDEF to "8bcccbcc18b95.b" is the same as setting
LESSCHARSET to "ascii". Setting LESSCHARDEF to "8bcccbcc18b95.33b." is
the same as setting LESSCHARSET to "latin1".
Control and binary characters are displayed in blinking mode. Each such
character is displayed in caret notation if possible (e.g. ^A for
control-A). Caret notation is used only if inverting the 0100 bit
results in a normal printable character. Otherwise, the character is
displayed as an octal number preceded by a backslash. This octal format
can be changed by setting the LESSBINFMT environment variable to a
printf-style format string; the default is '\%o'. The blinking mode
display of control and binary characters can be changed or disabled by
preceding the LESSBINFMT format string with a "*" and one character to
select the mode: "*k" is blinking, "*d" is bold, "*u" is underlined, and
"*n" is normal (no special display attribute). For example, if
LESSBINFMT is "*u[%x]", binary characters are displayed in underlined
hexadecimal surrounded by brackets.
PROMPTS
The -P option allows you to tailor the prompt to your preference. The
string given to the -P option replaces the specified prompt string.
Certain characters in the string are interpreted specially. The prompt
mechanism is rather complicated to provide flexibility, but the ordinary
user need not understand the details of constructing personalized prompt
strings.
A percent sign followed by a single character is expanded according to
what the following character is:
%bX Replaced by the byte offset into the current input file. The b is
followed by a single character (shown as X above) which specifies
the line whose byte offset is to be used. If the character is a
"t", the byte offset of the top line in the display is used, an "m"
means use the middle line, a "b" means use the bottom line, a "B"
means use the line just after the bottom line, and a "j" means use
the "target" line, as specified by the -j option.
%B Replaced by the size of the current input file.
%E Replaced by the name of the editor (from the EDITOR environment
variable). See the discussion of the LESSEDIT feature below.
%f Replaced by the name of the current input file.
%i Replaced by the index of the current file in the list of input
files.
%lX Replaced by the line number of a line in the input file. The line
to be used is determined by the X, as with the %b option.
%L Replaced by the line number of the last line in the input file.
%m Replaced by the total number of input files.
%pX Replaced by the percent into the current input file. The line used
is determined by the X as with the %b option.
%s Same as %B.
%t Causes any trailing spaces to be removed. Usually used at the end
of the string, but may appear anywhere.
%x Replaced by the name of the next input file in the list.
If any item is unknown (for example, the file size if input is a pipe), a
question mark is printed instead.
The format of the prompt string can be changed depending on certain
conditions. A question mark followed by a single character acts like an
"IF": depending on the following character, a condition is evaluated.
If the condition is true, any characters following the question mark and
condition character, up to a period, are included in the prompt. If the
condition is false, such characters are not included. A colon appearing
between the question mark and the period can be used to establish an
"ELSE": any characters between the colon and the period are included in
the string if and only if the IF condition is false. Condition
characters (which follow a question mark) may be:
?a True if any characters have been included in the prompt so far.
?bX True if the byte offset of the specified line is known.
?B True if the size of current input file is known.
?e True if at end-of-file.
?f True if there is an input filename (that is, if input is not a
pipe).
?lX True if the line number of the specified line is known.
?L True if the line number of the last line in the file is known.
?m True if there is more than one input file.
?n True if this is the first prompt in a new input file.
?pX True if the percent into the current input file of the specified
line is known.
?s Same as "?B".
?x True if there is a next input file (that is, if the current input
file is not the last one).
Any characters other than the special ones (question mark, colon, period,
percent, and backslash) become literally part of the prompt. Any of the
special characters may be included in the prompt literally by preceding
it with a backslash.
Some examples:
?f%f:Standard input.
This prompt prints the filename, if known; otherwise the string "Standard
input".
?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
This prompt would print the filename, if known. The filename is followed
by the line number, if known, otherwise the percent if known, otherwise
the byte offset if known. Otherwise, a dash is printed. Notice how each
question mark has a matching period, and how the % after the %pt is
included literally by escaping it with a backslash.
?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
This prints the filename if this is the first prompt in a file, followed
by the "file N of N" message if there is more than one input file. Then,
if we are at end-of-file, the string "(END)" is printed followed by the
name of the next file, if there is one. Finally, any trailing spaces are
truncated. This is the default prompt. For reference, here are the
defaults for the other two prompts (-m and -M respectively). Each is
broken into two lines here for readability only.
?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
?pB%pB\%:byte %bB?s/%s...%t
?f%f .?n?m(file %i of %m) ..?ltline %lt?L/%L. :byte %bB?s/%s. .
?e(END) ?x- Next\: %x.:?pB%pB\%..%t
And here is the default message produced by the = command:
?f%f .?m(file %i of %m) .?ltline %lt?L/%L. .
byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
The prompt expansion features are also used for another purpose: if an
environment variable LESSEDIT is defined, it is used as the command to be
executed when the v command is invoked. The LESSEDIT string is expanded
in the same way as the prompt strings. The default value for LESSEDIT
is:
%E ?lm+%lm. %f
Note that this expands to the editor name, followed by a + and the line
number, followed by the file name. If your editor does not accept the
"+linenumber" syntax, or has other differences in invocation syntax, the
LESSEDIT variable can be changed to modify this default.
ENVIRONMENT VARIABLES
COLUMNS
Sets the number of columns on the screen. Takes precedence over the
number of columns specified by the TERM variable.
EDITOR
The name of the editor (used for the v command).
HOME Name of the user's home directory (used to find a .less file).
LESS Flags which are passed to less automatically.
LESSBINFMT
Format for displaying non-printable, non-control characters.
LESSCHARDEF
Defines a character set.
LESSCHARSET
Selects a predefined character set.
LESSEDIT
Editor prototype string (used for the v command). See discussion
under PROMPTS.
LESSHELP
Name of the help file.
LINES
Sets the number of lines on the screen. Takes precedence over the
number of lines specified by the TERM variable.
SHELL
The shell used to execute the ! command, as well as to expand
filenames.
TERM The type of terminal on which less is being run.
SEE ALSO
lesskey(1)
WARNINGS
The = command and prompts (unless changed by -P) report the line number
of the line at the top of the screen, but the byte and percent of the
line at the bottom of the screen.
If the :e command is used to name more than one file, and one of the
named files has been viewed previously, the new files may be entered into
the list in an unexpected order.
The handling of national character sets is nonstandard as well as
insufficient for multibyte characters. It will probably change in a
later release.