Table of Contents
Both the KDE and GNOME desktop environments have adopted a similarformat for "desktop entries", or configuration files describing how aparticular program is to be launched, how it appears in menus, etc.It is to the larger community's benefit that a unified standard beagreed upon by all parties such that interoperation between the twoenvironments, and indeed any additional environments that implementthe specification, becomes simpler.
Desktop entry files should have the .desktopextension, except for files of TypeDirectory which should have the.directory extension. Determining file type on basisof extension makes determining the file type very easy and quick.When no file extension is present, the desktop system shouldfall back to recognition via "magic detection".
Desktop entry files are encoded in UTF-8. A file is interpreted as aseries of lines that are separated by linefeed characters. Case issignificant everywhere in the file.
Compliant implementations MUST not remove any fields from the file,even if they don't support them. Such fields must be maintained in alist somewhere, and if the file is "rewritten", they will be included.This ensures that any desktop-specific extensions will be preservedeven if another system accesses and changes the file.
Lines beginning with a # and blank lines areconsidered comments and will be ignored, however they should bepreserved across reads and writes of the desktop entry file.
Comment lines are uninterpreted and may contain any character(except for LF). However, using UTF-8 for comment lines thatcontain characters not in ASCII is encouraged.
A group header with name groupname is a line in theformat:
[groupname]
Group names may contain all ASCII characters except for[ and ] and control characters.
Multiple groups may not have the same name.
All {key,value} pairs following a group header untila new group header belong to the group.
The basic format of the desktop entry file requires that there bea group header named Desktop Entry. There maybe other groups present in the file, but this is the mostimportant group which explicitly needs to be supported. Thisgroup should also be used as the "magic key" for automatic MIMEtype detection. There should be nothing preceding this group inthe desktop entry file but possibly one or more comments.
Entries in the file are {key,value} pairs in theformat:
Key=Value
Space before and after the equals sign should be ignored; the= sign is the actual delimiter.
Only the characters A-Za-z0-9- may be used inkey names.
As the case is significant, the keys Name andNAME are not equivalent.
Multiple keys in the same group may not have the same name. Keys indifferent groups may have the same name.
The value types recognized are string,localestring,boolean, andnumeric.
Values of type string may contain all ASCII characters except for control characters.
Values of type localestring are user displayable, and are encoded in UTF-8.
Values of type boolean must either be the string true or false.
Values of type numeric must be a valid floating point number as recognized by the %f specifier for scanf in the C locale.
The escape sequences \s, \n,\t, \r, and\\ are supported for values of typestring and localestring, meaningASCII space, newline, tab, carriage return, and backslash, respectively.
Some keys can have multiple values. In such a case, the value of the keyis specified as a plural: for example, string(s). Themultiple values should be separated by a semicolon, and the value of thekey should have a semicolon as trailing character. Semicolons in thesevalues need to be escaped using \;.
Keys with type localestring may be postfixed by[LOCALE],where LOCALE is the locale type of theentry. LOCALE must be of the formlang_COUNTRY.ENCODING@MODIFIER_,COUNTRY.,and ENCODING@may be omitted. If a postfixed key occurs, the samekey must be also present without the postfix.MODIFIER
When reading in the desktop entry file, the value of the key isselected by matching the current POSIX locale for theLC_MESSAGES category against theLOCALE postfixes of all occurrencesof the key, with the. partstripped.ENCODING
The matching is done as follows. IfLC_MESSAGES is of the formlang_COUNTRY.ENCODING@MODIFIERlang_COUNTRY@MODIFIERlang_COUNTRYlang@MODIFIERlang by itselfwill be attempted. Finally, if no matching key is found therequired key without a locale specified is used. The encodingfrom the LC_MESSAGES value is ignoredwhen matching.
If LC_MESSAGES does not have a MODIFIERfield, then no key with a modifier will be matched. Similarly, ifLC_MESSAGES does not have a COUNTRYfield, then no key with a country specified will be matched. IfLC_MESSAGES just has a lang field, thenit will do a straight match to a key with a similar value. Thefollowing table lists possible matches of various LC_MESSAGES values inthe order in which they are matched. Note that theENCODING field isn't shown.
Table 1. Locale Matching
LC_MESSAGES value | Possible keys in order of matching |
|---|---|
| |
| lang, default value |
| lang, default value |
lang | lang, default value |
For example, if the current value of the LC_MESSAGES categoryis sr_YU@Latn and the desktop file includes:
Name=FooName[sr_YU]=...Name[sr@Latn]=...Name[sr]=...
then the value of the Name keyed by sr_YU is used.
Keys are either OPTIONAL or REQUIRED. If a key is OPTIONAL it may ormay not be present in the file. However, if it isn't, theimplementation of the standard should not blow up, it must providesome sane defaults.
Some keys only make sense in the context when another particular keyis also present and set to a specific value. Those keys should not beused if the particular key is not present or not set to the specificvalue. For example, the Terminal key can only be usedwhen the value of the Type key isApplication.
If a REQUIRED key is only valid in the context of another key set to aspecific value, then it has to be present only if the other key is set tothe specific value. For example, the URL key has to bepresent when and only when when the value of the Typekey is Link.
Some example keys: Name[C], Comment[it].
Table 2. Standard Keys
| Key | Description | Value Type | REQ? | Type |
|---|---|---|---|---|
Type | This specification defines 3 types of desktop entries: Application (type 1), Link (type 2) and Directory (type 3). To allow the addition of new types in the future, implementations should ignore desktop entries with an unknown type. | string | YES | |
Version | Version of the Desktop Entry Specification that the desktop entry conforms with. Entries that confirm with this version of the specification should use 1.0. Note that the version field is not required to be present. | string | NO | 1-3 |
Name | Specific name of the application, for example "Mozilla". | localestring | YES | 1-3 |
GenericName | Generic name of the application, for example "Web Browser". | localestring | NO | 1-3 |
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 | 1-3 |
Comment | Tooltip for the entry, for example "View sites on the Internet". The value should not be redundant with the values of Name and GenericName. | localestring | NO | 1-3 |
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, the algorithm described in the Icon Theme Specification will be used to locate the icon. | localestring | NO | 1-3 |
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 | 1-3 |
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 | 1-3 |
TryExec | Path to an executable file on disk used to determine if the program is actually installed. If the path is not an absolute path, the file is looked up in the $PATH environment variable. If the file is not present or if it is not executable, the entry may be ignored (not be used in menus, for example). | string | NO | 1 |
Exec | Program to execute, possibly with arguments. | string | YES | 1 |
Path | If entry is of type Application, the working directory to run the program in. | string | NO | 1 |
Terminal | Whether the program runs in a terminal window. | boolean | NO | 1 |
MimeType | The MIME type(s) supported by this application. | string(s) | NO | 1 |
Categories | Categories in which the entry should be shown in a menu (for possible values see the Desktop Menu Specification). | string(s) | NO | 1 |
StartupNotify | If true, it is KNOWN that the application will send a "remove" message when started with the DESKTOP_STARTUP_ID environment variable set. If false, it is KNOWN that the application does not work with startup notification at all (does not shown any window, breaks even when using StartupWMClass, etc.). If absent, a reasonable handling is up to implementations (assuming false, using StartupWMClass, etc.). (See the Startup Notification Protocol Specification for more details). | boolean | NO | 1 |
StartupWMClass | If specified, 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 | 1 |
URL | If entry is Link type, the URL to access. | string | YES | 2 |
The Exec key must contain a command line.A command line consists of an executable program optionally followedby one or more arguments.The executable program can either be specified with its full path orwith the name of the executable only. If no full path is provided theexecutable is looked up in the $PATH environment variable used by thedesktop environment.The name or path of the executable program may not contain the equalsign ("="). Arguments are separated by a space.
Arguments may be quoted in whole. If an argument contains a reservedcharacter the argument must be quoted. The rules for quoting ofarguments is also applicable to the executable name or path of theexecutable program as provided.
Quoting must be done by enclosing the argument between double quotesand escaping the double quote character, backtick character ("`"),dollar sign ("$") and backslash character ("\") by preceding it with anadditional backslash character. Implementations must undo quoting beforeexpanding field codes and before passing the argument to the executableprogram. Reserved characters are space (" "), tab, newline, doublequote, single quote ("'"), backslash character ("\"),greater-than sign (">"), less-than sign ("<"),tilde ("~"), vertical bar ("|"), ampersand ("&"), semicolon (";"),dollar sign ("$"), asterisk ("*"), question mark ("?"), hash mark ("#"),parenthesis ("(") and (")") and backtick character ("`").
Note that the general escape rule for values of type string states thatthe backslash character can be escaped as ("\\") as well and that thisescape rule is applied before the quoting rule. As such, tounambiguously represent a literal backslash character in a quotedargument in a desktop entry file requires the use of four successivebackslash characters ("\\\\"). Likewise, a literal dollar sign in aquoted argument in a desktop entry file is unambiguously representedwith ("\\$").
A number of special field codes have been defined which will beexpanded by the file manager or program launcher when encounteredin the command line.Field codes consist of the percentage character ("%") followed byan alpha character. Literal percentage characters must be escapedas %%.Deprecated field codes should be removed from the command line andignored.Field codes are expanded only once, the string that is used toreplace the field code should not be checked for field codes itself.
Command lines that contain a field code that is not listed in thisspecification are invalid and must not be processed, in particularimplementations may not introduce support for field codes not listedin this specification. Extensions, if any, should be introduced bymeans of a new key.
Implementations must take care not to expand field codes into multiplearguments unless explicitly instructed by this specification.This means that name fields, filenames and other replacements thatcan contain spaces must be passed as a single argumentto the executable program after expansion.
Although the Exec key is defined to have a valueof the type string, which is limited to ASCII characters, field codeexpansion may introduce non-ASCII characters in arguments.Implementations must take care that all characters in argumentspassed to the executable program are properly encoded according tothe applicable locale setting.
Recognized field codes are as follows:
| Code | Description |
|---|---|
%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. Each file is passed as a separate argument to the executable program. |
%u | A single URL. Local files may either be passed as file: URLs or as file path. |
%U | A list of URLs. Each URL is passed as a separate argument to the executable program. Local files may either be passed as file: URLs or as file path. |
%d | Deprecated. |
%D | Deprecated. |
%n | Deprecated. |
%N | Deprecated. |
%i | The Icon key of the desktop entry expanded as two arguments, first --icon and then the value of the Icon key. Should not expand to any arguments if the Icon key is empty or missing. |
%c | The translated name of the application as listed in the appropriate Name key in 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 | Deprecated. |
%m | Deprecated. |
A command line may contain at most one %f, %u, %F or %U field code.If the application should not open anyfile the %f, %u, %F and %U field codes must be removed from thecommand line and ignored.
Field codes must not be used inside a quoted argument, the result offield code expansion inside a quoted argument is undefined. The %F and%U field codes may only be used as an argument on their own.
The MimeType key is used to indicate the MIMETypes that an application knows how to handle. It is expected thatfor some applications this list could become long. An applicationis expected to be able to reasonably open files of these typesusing the command listed in the Exec key.
There should be no priority for MIME Types in this field, or anyform of priority in the desktop file. Priority for applicationsis handled external to the .desktop files.
If the standard is to be amended with a new {key,value} pair whichshould be applicable to all supporting parties, a group discussionwill take place. This is the preferred method for introducingchanges. If one particular party wishes to add a field for personaluse, they should prefix the key with the string X-,e.g. PRODUCTX-NewDesktop-Foo, following the precedent set by other IETF and RFCstandards.
Alternatively, fields can be placed in their own group, where they maythen have arbitrary key names. If this is the case, the group shouldfollow the scheme outlined above,i.e. [X- orsomething similar. These steps will avoid namespace clashes betweendifferent yet similar environments.PRODUCTGROUPNAME]
[Desktop Entry]Version=1.0Type=ApplicationName=Foo ViewerComment=The best viewer for Foo objects available!TryExec=fooviewExec=fooview %FIcon=fooviewMimeType=image/x-foo;X-KDE-Library=libfooviewX-KDE-FactoryName=fooviewfactoryX-KDE-ServiceType=FooService
For historical reasons KDE is using some KDE-specific extensionsthat are currently not prefixed by a X-KDE- prefix.
KDE specific keys: ServiceTypes, DocPath, Keywords, InitialPreference
KDE specific types: ServiceType, Service and FSDevice
KDE uses the following additional keys for desktop entries of theFSDevice type.
Table B.1. FSDevice Specific Keys
As this standard is quite old there are some deprecated items thatmay 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.
The Encoding key is deprecated. It was used to specify whether keys of type localestring were encoded in UTF-8 or in the specified locale. Possible values are UTF-8 and Legacy-Mixed. See Appendix D, The Legacy-Mixed Encoding (Deprecated) for more details.
Deprecated Exec field codes: %m (the mini-icon associated with the desktop entry, this should be expanded as two arguments, --miniicon and the content of the MiniIcon key, it can also be ignored by expanding it to no arguments), %v (the device as listed in the Dev key in the desktop file), %d (the directory of a file), %D (the directories of files), %n (the base name of a file) and %N (the base names of files).
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.
The SwallowTitle and SwallowExec keys are deprecated. The SwallowTitle key is of type localestring and specifies the title of the window if is swallowed onto the panel. The SwallowExec key is of type string and specifies the program to exec if swallowed app is clicked.
The SortOrder key is deprecated. It is of type string(s) and may be used to specify the order in which to display files. The Desktop Menu Specification defines another mechanism for defining the order of menu items.
The FilePattern key is deprecated. The value is 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.
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.
Legacy-Mixed Encoding (Deprecated)The Legacy-Mixed encoding corresponds to thetraditional encoding of desktop files in older versions of the GNOME andKDE desktop files. In this encoding, the encoding of eachlocalestring key is determined by the locale tag forthat key, if any, instead of being UTF-8. For keys without a locale tag,the value must contain only ASCII characters.
If the file specifies an unsupported encoding, the implementationshould either ignore the file, or, if the user has requested a directoperation on the file (such as opening it for editing), display anappropriate error indication to the user.
In the absence of an Encoding key, the implementation may chooseto autodetect the encoding of the file by using such factorsas:
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 shouldtreat a file without an Encoding key in the same way as a file with anunsupported Encoding key.
If the locale tag includes an . part, then that determinesthe encoding for the line. Otherwise, the encoding is determinedby the language, orENCODINGlang_COUNTRY
| Encoding | Aliases | Tags |
|---|---|---|
| ARMSCII-8 (*) | hy | |
| BIG5 | zh_TW | |
| CP1251 | be bg | |
| EUC-CN | GB2312 | zh_CN |
| EUC-JP | ja | |
| EUC-KR | ko | |
| GEORGIAN-ACADEMY (*) | ||
| GEORGIAN-PS (*) | ka | |
| ISO-8859-1 | br ca da de en es eu fi fr gl it nl no pt sv wa | |
| ISO-8859-2 | cs hr hu pl ro sk sl sq sr | |
| ISO-8859-3 | eo | |
| ISO-8859-5 | mk sp | |
| ISO-8859-7 | el | |
| ISO-8859-9 | tr | |
| ISO-8859-13 | lt lv mi | |
| ISO-8859-14 | cy ga | |
| ISO-8859-15 | et | |
| KOI8-R | ru | |
| KOI8-U | uk | |
| TCVN-5712 (*) | TCVN | vi |
| TIS-620 | th | |
| VISCII |
The name given here is listed here is typically thecanonical name for the encoding in the GNU C Library'siconv facility. Encodings marked with (*) are notcurrently supported by the GNU C Library; for this reason,implementations may choose to ignore lines in desktopfiles that resolve to this encoding. Desktop files withthese encodings are currently rare or non-existent.
Other names for the encoding found in existing desktopfiles.
Language tags for which this is the default encoding.
This table above covers all tags and encodings that are known tobe currently in use. Implementors may choose to supportencodings not in the above set. For tags without defaults listedin the above table, desktop file creators must specify the. part of the locale tag.ENCODING
Matching the . part of the locale tag against a localename or alias should be done by stripping all punctuationcharacters from both the tag and the name or alias, convertingboth name and alias to lowercase, and comparing the result.This is necessary because, for example, ENCODINGBig5 is frequentlyfound instead of BIG5 and georgianacademy instead ofGEORGIAN-ACADEMY. Desktop files creators should, however, usethe name as it appears in the "Encoding" column above.
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