Version 0.9.4 7 July 2003 Preston Brown

pbrown@kde.org

Jonathan Blandford

jrb@redhat.com

Owen Taylor

otaylor@gtk.org

Both the KDE and GNOME desktop environments have adopted a similar format for "desktop entries", or configuration files describing how a particular program is to be launched, how it appears in menus, etc. It is to the larger community's benefit that a unified standard be agreed upon by all parties such that interoperation between the two environments, and indeed any additional environments that implement the specification, becomes simpler. These desktop entry files should have the extension .desktop. Determining file type on basis of extension makes determining the file type very easy and quick. When no file extension is present, the desktop system should fall back to recognition via "magic detection". Desktop entries which describe how a directory is to be formatted/displayed should be simply called .directory. The basic format of the desktop entry file requires that there be a "group" header named [Desktop Entry]. This "group" entry denotes that all {key,value} pairs following it belong in the Desktop Entry group. There may be other groups present in the file (see MIME types discussion below), but this is the most important group which explicitly needs to be supported. This group should also be used as the "magic key" for automatic MIME type detection. There should be nothing proceeding this group in the desktop entry file but possibly one or more comments (see below). Group headers may not contain the characters [ and ] as those delimit the header. Lines beginning with a # and blank lines are considered comments and will be ignored, however they should be preserved across reads and writes of the desktop entry file. Compliant implementations MUST not remove any fields from the file, even if they don't support them. Such fields must be maintained in a list somewhere, and if the file is "rewritten", they will be included. This ensures that any desktop-specific extensions will be preserved even if another system accesses and changes the file. Entries in the file are {key,value} pairs in the format: Name=Value Space before and after the equals sign should be ignored; the = sign is the actual delimiter. The escape sequences \s, \n, \t, \r, and \\ are supported, meaning ASCII space, newline, tab, carriage return, and backslash, respectively. The value types recognized are string, localestring, regexp, boolean (encoded as the string true/false), and numeric. The difference between string and localestring is that the value for a string key must contain only ASCII characters while the value of a localestring key may contain UTF-8 characters. Some keys can have multiple values; these should be separated by a semicolon. Those keys which have several values should have a semicolon as the trailing character. For lists of strings, semicolons are simply not allowed in the strings, there is no escape mechanism. Keys with type localestring may be postfixed by [LOCALE], where LOCALE is the locale type of the entry. LOCALE must be of the form lang_COUNTRY.ENCODING@MODIFIER, where _COUNTRY, .ENCODING, and @MODIFIER may be omitted. If a postfixed key occurs, the same key must be also present without the postfix. When reading in the desktop entry file, the value of the key is selected by matching the current POSIX locale for the LC_MESSAGES category against the LOCALE postfixes of all occurrences of the key, with the .ENCODING part stripped. The .ENCODING field is used only when the value of the Encoding key for the desktop entry file is Legacy-Mixed (see .) The matching of is done as follows. If LC_MESSAGES is of the form lang_COUNTRY.ENCODING@MODIFIER, then it will match a key of the form lang_COUNTRY@MODIFIER. If such a key does not exist, it will attempt to match lang_COUNTRY followed by lang@MODIFIER. Then, a match against lang by itself will be attempted. Finally, if no matching key is found the required key without a locale specified is used. The encoding from the LC_MESSAGES value is ignored when matching. If LC_MESSAGES does not have a MODIFIER field, then no key with a modifier will be matched. Similarly, if LC_MESSAGES does not have a COUNTRY field, then no key with a country specified will be matched. If LC_MESSAGES just has a lang field, then it will do a straight match to a key with a similar value. The following table lists possible matches of various LC_MESSAGES values in the order in which they are matched. Note that the ENCODING field isn't shown. LC_MESSAGES value Possible keys in order of matching lang_COUNTRY@MODIFIER lang_COUNTRY@MODIFIER, lang_COUNTRY, lang@MODIFIER, lang, default value lang_COUNTRY lang_COUNTRY, lang, default value lang@MODIFIER lang@MODIFIER, lang, default value lang lang, default value For example, if the current value of the LC_MESSAGES category is sr_YU@Latn and the desktop file includes: Name=Foo Name[sr_YU]=... Name[sr@Latn]=... Name[sr]=... then the value of the Name keyed by sr_YU is used. Case is significant. The keys Name and NAME are not equivalent. The same holds for group names. Key values are case sensitive as well. Keys are either OPTIONAL or REQUIRED. If a key is optional it may or may not be present in the file. However, if it isn't, the implementation of the standard should not blow up, it must provide some sane defaults. Additionally, keys either MUST or MAY be supported by a particular implementation. Some keys only make sense in the context when another particular key is also present. Some example keys: Name[C], Comment[it]. Key Description Value Type REQ? MUST? Type Type There are 4 types of desktop entries: Application, Link, FSDevice and Directory. string YES YES Version Version of Desktop Entry Specification (While the version field is not required to be present, it should be in all newer implementations of the Desktop Entry Specification. If the version number is not present, a "pre-standard" desktop entry file is to be assumed). numeric NO YES 1-4 Encoding Encoding of the whole desktop entry file (UTF-8 or Legacy-Mixed). string YES YES 1-4 Name Specific name of the application, for example "Mozilla". localestring YES YES 1-4 GenericName Generic name of the application, for example "Web Browser". localestring NO YES 1-4 NoDisplay NoDisplay means "this application exists, but don't display it in the menus". This can be useful to e.g. associate this application with MIME types, so that it gets launched from a file manager (or other apps), without having a menu entry for it (there are tons of good reasons for this, including e.g. the netscape -remote, or kfmclient openURL kind of stuff). boolean NO NO 1-4 Comment Tooltip for the entry, for example "View sites on the Internet", should not be redundant with Name or GenericName. localestring NO YES 1-4 Icon Icon to display in file manager, menus, etc. If the name is an absolute path, the given file will be used. If the name is not an absolute path, an implementation-dependent search algorithm will be used to locate the icon. Icons may be localized with the Icon[xx]= syntax. string NO YES 1-4 Hidden Hidden should have been called Deleted. It means the user deleted (at his level) something that was present (at an upper level, e.g. in the system dirs). It's strictly equivalent to the .desktop file not existing at all, as far as that user is concerned. This can also be used to "uninstall" existing files (e.g. due to a renaming) - by letting make install install a file with Hidden=true in it. boolean NO NO 1-4 FilePattern A list of regular expressions to match against for a file manager to determine if this entry's icon should be displayed. Usually simply the name of the main executable and friends. regexp(s) NO NO 1 TryExec File name of a binary on disk used to determine if the program is actually installed. If not, entry may not show in menus, etc. string NO NO 1 Exec Program to execute, possibly with arguments. string NO YES 1 Path If entry is of type Application, the working directory to run the program in. string NO YES 1 Terminal Whether the program runs in a terminal window. boolean NO YES 1 SwallowTitle If entry is swallowed onto the panel, this should be the title of the window. localestring NO NO 1 SwallowExec Program to exec if swallowed app is clicked. string NO NO 1 Actions Additional actions possible, see MIME type discussion in . string(s) NO YES 1 MimeType The MIME type(s) supported by this entry. regexp(s) NO NO 1 SortOrder This may specify the order in which to display files. string(s) NO NO 4 Dev The device to mount. string NO NO 3 FSType The type of file system to try to mount. string NO NO 3 MountPoint The mount point of the device in question. string NO NO 3 ReadOnly Specifies whether or not the device is read only. boolean NO NO 3 UnmountIcon Icon to display when device is not mounted. Mounted devices display icon from the Icon key. UnmountIcons may be localized with the UnmountIcon[xx]= syntax. string NO NO 3 URL If entry is Link type, the URL to access. string NO YES 2 Categories Categories in which the entry should be shown in a menu (for possible values see the Desktop Menu Specification). string(s) NO NO 1 OnlyShowIn, NotShowIn A list of strings identifying the environments that should display/not display a given desktop entry. Only one of these keys, either OnlyShowIn or NotShowIn, may appear in a group (for possible values see the Desktop Menu Specification). string(s) NO NO 1-4 StartupNotify If true, it is KNOWN that the application will send a "remove" message when started with the DESKTOP_LAUNCH_ID environment variable set (see the Startup Notification Protocol Specification for more details). boolean NO NO 1 StartupWMClass If true, it is KNOWN that the application will map at least one window with the given string as its WM class or WM name hint (see the Startup Notification Protocol Specification for more details). string NO NO 1 Desktop entry files are encoded as lines of 8-bit characters separated by LF characters. Key names must contain only the characters A-Za-z0-9- Group names may contain all ASCII characters except for [ and ] and control characters. Values of type string may contain all ASCII characters except for control characters. Values of type boolean must either be the string true or false. Numeric values must be a valid floating point number as recognized by the %f specifier for scanf. Comment lines are uninterpreted and may contain any character (except for LF). However, using UTF-8 for comment lines that contain characters not in ASCII is encouraged. The encoding for values of type localestring is determined by the Encoding field. Each Exec field may take a number of arguments which will be expanded by the file manager or program launcher and passed to the program if necessary. Literal % characters must be escaped as %%, and adding new format characters is not allowed. It's a fatal error to have an Exec field with a format character not given in the spec (exception to this are the deprecated format characters which can be ignored, that is expanded to no parameters, by the implementation). Again for emphasis: nonstandard extensions are not allowed here - you must add an X-Foo-Exec field if you have nonstandard Exec lines. The escaping of the exec parameters is done in the way the mailcap specification describes. Take a look at RFC 1524 for more information. Recognized fields are as follows: %f A single file name, even if multiple files are selected. The system reading the desktop entry should recognize that the program in question cannot handle multiple file arguments, and it should should probably spawn and execute multiple copies of a program for each selected file if the program is not able to handle additional file arguments. If files are not on the local file system (i.e. are on HTTP or FTP locations), the files will be copied to the local file system and %f will be expanded to point at the temporary file. Used for programs that do not understand the URL syntax. %F A list of files. Use for apps that can open several local files at once. %u A single URL. %U A list of URLs. %d Directory containing the file that would be passed in a %f field. %D List of directories containing the files that would be passed in to a %F field. %n A single filename (without path). %N A list of filenames (without paths). %i The Icon field of the desktop entry expanded as two parameters, first --icon and then the contents of the Icon field. Should not expand as any parameters if the Icon field is empty or missing. %c The translated Name field associated with the desktop entry. %k The location of the desktop file as either a URI (if for example gotten from the vfolder system) or a local filename or empty if no location is known. %v The name of the Device entry in the desktop file. It is in every desktop's best interest to have thorough support for MIME types. The old /etc/mailcap and /etc/mime.types files are rather limited in scope and frankly, are outdated. Various desktop systems have come up with different ways of extending this original system, but none are compatible with each other. The Desktop Entry Specification hopes to be able to provide the beginnings of a solution to this problem. At a very basic level, the Exec key provides the default action to take when the program described by a desktop entry is used to open a document or data file. Usually this consists of some action along the lines of kedit %f or ee %f. This is a good start, but it isn't as flexible as it can be. Let us first establish that a program which supports a MIME type or multiple MIME types may be able to support multiple actions on those MIME types as well. The desktop entry may want to define additional actions in addition to the default. The top level Exec key describes the default action; Let us define this action to also be known as the "Open" action. Additional actions which might be possible include "View", "Edit", "Play", etc. A further revision of this document will probably specify several "standard" actions in addition to the default "Open" action, but in all cases, the number of actions is arbitrary. Let us use a sound player as a simple example. Call it sp. The default Exec (Open) action for this program would likely look something like: Exec=sp %u However, imagine the sound player also supports editing of sound files in a graphical manner. We might wish to define an additional action which could accommodate this. Adding the action would be performed like this: Actions=Edit; [Desktop Action Edit] Exec=sp -edit %u As you can see, defining the action "Edit" will enable an additional group of the name [Desktop Action actionname] to be read. This group can contain an additional Exec line, as well as possibly other information like a new Name, Comment, Icon, and Path. Thus right-clicking on a .wav file will show both the default "Open" action and this "Edit" action to both be displayed as choices in the context-menu. A left click (double or single, whichever the file manager implements) would cause the default action to take place. These are implementation specific details which are up to the implementer, and are not enforced by this standard. If no DefaultApp is specified for a particular MIME type, any one of the programs registered which claim to be able to handle the MIME type may become the default handler. This behaviour is undefined and implementation specific. KDE doesn't use a DefaultApp anymore, but assigns a preference number to each program, so that the highest number is the one chosen for handling the MIME type. If the standard is to be amended with a new {key,value} pair which should be applicable to all supporting parties, a group discussion will take place. This is the preferred method for introducing changes. If one particular party wishes to add a field for personal use, they should prefix the key with the string X-PRODUCT, e.g. X-NewDesktop-Foo, following the precedent set by other IETF and RFC standards. Alternatively, fields can be placed in their own group, where they may then have arbitrary key names. If this is the case, the group should follow the scheme outlined above, i.e. [X-PRODUCT GROUPNAME] or something similar. These steps will avoid namespace clashes between different yet similar environments. [Desktop Entry] Version=1.0 Type=Application Encoding=UTF-8 Name=Foo Viewer Comment=The best viewer for Foo objects available! TryExec=fooview Exec=fooview %F Icon=fooview.png MimeType=image/x-foo X-KDE-Library=libfooview X-KDE-FactoryName=fooviewfactory X-KDE-ServiceType=FooService [Desktop Action Inverse] Exec=fooview --inverse %f Name=Foo Viewer (inverse image) [Desktop Action Edit] Exec=fooview --edit %f Name=Foo Viewer (edit image) Icon=fooview-edit.png During the time KDE added some extensions that are currently not prefixed by the X- prefix, but should be in future KDE releases. Keys added by KDE: ServiceTypes, DocPath, Keywords, InitialPreference Types added by KDE: ServiceType, Service As this standard is quite old there are some deprecated items that may or may not be used by several implementations. Type=MimeType is deprecated as there is a new standard for this now, see the Shared MIME-info Database specification for more information. In consequence the Keys Patterns (various file name extensions associated with the MIME type) and DefaultApp (the default application associated with this MIME type) are also deprecated. Using .kdelnk instead of .desktop as the file extension is deprecated. Using [KDE Desktop Entry] instead of [Desktop Entry] as header is deprecated. Encoding=Legacy-Mixed, which allowed localestrings in the encoding of the specified locale, is deprecated. Deprecated Exec parameters: %m (the mini-icon associated with the desktop entry, this should be expanded as two parameters, --miniicon and the content of the MiniIcon field, it can also be ignored by expanding it to no parameters). Deprecated keys: MiniIcon (small icon for menus, etc), TerminalOptions (if the program runs in a terminal, any options that should be passed to the terminal emulator before actually executing the program), Protocols, Extensions, BinaryPattern, MapNotify. Historically some booleans have been represented by the numeric entries 0 or 1. With this version of the standard they are now to be represented as a boolean string. However, if an implementation is reading a pre-1.0 desktop entry, it should interpret 0 and 1 as false and true, respectively. Historically lists have been comma separated. This is inconsistent with other lists which are separated by a semicolon. When reading a pre-1.0 desktop entry, comma separated lists should continue to be supported. The Legacy-Mixed encoding corresponds to the traditional encoding of desktop files in older versions of the GNOME and KDE desktop files. In this encoding, the encoding of each localestring key is determined by the locale tag for that key, if any. For keys without a locale tag, the value must contain only ASCII characters. If the file specifies an unsupported encoding, the implementation should either ignore the file, or, if the user has requested a direct operation on the file (such as opening it for editing), display an appropriate error indication to the user. In the absence of an Encoding line, the implementation may choose to autodetect the encoding of the file by using such factors as: The location of the file on the file system Whether the contents of the file are valid UTF-8 If the implementation does not perform such auto-detection, it should treat a file without an Encoding key in the same way as a file with an unsupported Encoding Key. If the locale tag includes an .ENCODING part, then that determines the encoding for the line. Otherwise, the encoding is determined by the language, or lang_COUNTRY pair from the locale tag, according to the following table. Encoding Aliases Tags ARMSCII-8 (*)hy BIG5zh_TW CP1251be bg EUC-CNGB2312zh_CN EUC-JPja EUC-KRko GEORGIAN-ACADEMY (*) GEORGIAN-PS (*)ka ISO-8859-1br ca da de en es eu fi fr gl it nl no pt sv wa ISO-8859-2cs hr hu pl ro sk sl sq sr ISO-8859-3 eo ISO-8859-5mk sp ISO-8859-7el ISO-8859-9tr ISO-8859-13lt lv mi ISO-8859-14cy ga ISO-8859-15et KOI8-Rru KOI8-Uuk TCVN-5712 (*)TCVNvi TIS-620th VISCII Encoding The name given here is listed here is typically the canonical name for the encoding in the GNU C Library's iconv facility. Encodings marked with (*) are not currently supported by the GNU C Library; for this reason, implementations may choose to ignore lines in desktop files that resolve to this encoding. Desktop files with these encodings are currently rare or non-existent. Aliases Other names for the encoding found in existing desktop files. Tags Language tags for which this is the default encoding. This table above covers all tags and encodings that are known to be currently in use. Implementors may choose to support encodings not in the above set. For tags without defaults listed in the above table, desktop file creators must specify the .ENCODING part of the locale tag. Matching the .ENCODING part of the locale tag against a locale name or alias should be done by stripping all punctuation characters from both the tag and the name or alias, converting both name and alias to lowercase, and comparing the result. This is necessary because, for example, Big5 is frequently found instead of BIG5 and georgianacademy instead of GEORGIAN-ACADEMY. Desktop files creators should, however, use the name as it appears in the "Encoding" column above.