| Suffix | File type |
| - | backup file |
| .C | C++ source code, equivalent to .cc |
| .F | Fortran source with cpp(1) directives |
| | or file compressed using freeze |
| .S | assembler source with cpp(1) directives |
| .Y | file compressed using yabba |
| .Z | file compressed using compress(1) |
| .[0-9]+gf | TeX generic font files |
| .[0-9]+pk | TeX packed font files |
| .[1-9] | manual page for the corresponding section |
| .[1-9][a-z] | manual page for section plus subsection |
| .a | static object code library |
| .ad | X application default resource file |
| .ada | Ada source (may be body, spec, or combination) |
| .adb | Ada body source |
| .ads | Ada spec source |
| .afm | PostScript font metrics |
| .al | Perl autoload file |
| .am | automake(1) input file |
| .arc | arc(1) archive |
| .arj | arj(1) archive |
| .asc | PGP ASCII-armoured data |
| .asm | (GNU) assember source file |
| .au | Audio sound file |
| .aux | LaTeX auxiliary file |
| .avi | (msvideo) movie |
| .awk | AWK language program |
| .b | LILO boot loader image |
| .bak | backup file |
| .bash | bash(1) shell script |
| .bb | basic block list data produced by |
| | gcc -ftest-coverage |
| .bbg | basic block graph data produced by |
| | gcc -ftest-coverage |
| .bbl | BibTeX output |
| .bdf | X font file |
| .bib | TeX bibliographic database, BibTeX input |
| .bm | bitmap source |
| .bmp | bitmap |
| .bz2 | file compressed using bzip2(1) |
| .c | C source |
| .cat | message catalog files |
| .cc | C++ source |
| .cf | configuration file |
| .cfg | configuration file |
| .cgi | WWW content generating script or program |
| .cls | LaTeX Class definition |
| .class | Java compiled byte-code |
| .conf | configuration file |
| .config | configuration file |
| .cpp | equivalent to .cc |
| .csh | csh(1) shell script |
| .cxx | equivalent to .cc |
| .dat | data file |
| .deb | Debian software package |
| .def | Modula-2 source for definition modules |
| .def | other definition files |
| .desc | initial part of mail message unpacked with |
| | munpack(1) |
| .diff | file differences (diff(1) command output) |
| .dir | dbm data base directory file |
| .doc | documentation file |
| .dsc | Debian Source Control (source package) |
| .dtx | LaTeX package source file |
| .dvi | TeX’s device independent output |
| .el | Emacs-Lisp source |
| .elc | compiled Emacs-Lisp source |
| .eps | encapsulated PostScript |
| .exp | Expect source code |
| .f | Fortran source |
| .f77 | Fortran 77 source |
| .f90 | Fortran 90 source |
| .fas | pre-compiled Common-Lisp |
| .fi | Fortran include files |
| .fig | FIG image file (used by xfig(1)) |
| .fmt | TeX format file |
| .gif | Compuserve Graphics Image File format |
| .gmo | GNU format message catalog |
| .gsf | Ghostscript fonts |
| .gz | file compressed using gzip(1) |
| .h | C or C++ header files |
| .help | help file |
| .hf | equivalent to .help |
| .hlp | equivalent to .help |
| .htm | poor man’s .html |
| .html | HTML document used with the World Wide Web |
| .hqx | 7-bit encoded Macintosh file |
| .i | C source after preprocessing |
| .icon | bitmap source |
| .idx | reference or datum-index file for hypertext |
| | or database system |
| .image | bitmap source |
| .in | configuration template, especially for GNU Autoconf |
| .info | files for the Emacs info browser |
| .info-[0-9]+ | splitted info files |
| .ins | LaTeX package install file for docstrip |
| .itcl | itcl source code; |
| | itcl ([incr Tcl]) is an OO extension of tcl |
| .java | a Java source file |
| .jpeg | Joint Photographic Experts Group format |
| .jpg | poor man’s .jpeg |
| .kmap | lyx(1) keymap |
| .l | equivalent to .lex or .lisp |
| .lex | lex(1) or flex(1) files |
| .lha | lharc archive |
| .lib | Common-Lisp library |
| .lisp | Lisp source |
| .ln | files for use with lint(1) |
| .log | log file, in particular produced by TeX |
| .lsm | Linux Software Map entry |
| .lsp | Common-Lisp source |
| .lzh | lharc archive |
| .m | Objective-C source code |
| .m4 | m4(1) source |
| .mac | macro files for various programs |
| .man | manual page (usually source rather than formatted) |
| .map | map files for various programs |
| .me | Nroff source using the me macro package |
| .mf | Metafont (font generator for TeX) source |
| .mgp | MagicPoint file |
| .mm | sources for groff(1) in mm - format |
| .mo | Message catalog binary file |
| .mod | Modula-2 source for implementation modules |
| .mov | (quicktime) movie |
| .mp | Metapost source |
| .mp2 | MPEG Layer 2 (audio) file |
| .mp3 | MPEG Layer 3 (audio) file |
| .mpeg | movie file |
| .o | object file |
| .old | old or backup file |
| .orig | backup (original) version of a file, from patch(1) |
| .out | output file, often executable program (a.out) |
| .p | Pascal source |
| .pag | dbm data base data file |
| .patch | file differences for patch(1) |
| .pbm | portable bitmap format |
| .pcf | X11 font files |
| .pdf | Adobe Portable Data Format |
| | (use Acrobat/acroread or xpdf) |
| .perl | Perl source (see .ph, .pl and .pm) |
| .pfa | PostScript font definition files, ASCII format |
| .pfb | PostScript font definition files, binary format |
| .pgm | portable greymap format |
| .pgp | PGP binary data |
| .ph | Perl header file |
| .php | PHP program file |
| .php3 | PHP3 program file |
| .pid | File to store daemon pid (e.g. crond.pid) |
| .pl | TeX property list file or Perl library file |
| .pm | Perl module |
| .png | Portable Network Graphics file |
| .po | Message catalog source |
| .pod | perldoc(1) file |
| .ppm | portable pixmap format |
| .pr | bitmap source |
| .ps | PostScript file |
| .py | Python source |
| .pyc | compiled python |
| .qt | quicktime movie |
| .r | RATFOR source (obsolete) |
| .rej | patches that patch(1) couldn’t apply |
| .rpm | RedHat software package |
| .rtf | Rich Text Format file |
| .rules | rules for something |
| .s | assembler source |
| .sa | stub libraries for a.out shared libraries |
| .sc | sc(1) spreadsheed commands |
| .scm | Scheme source code |
| .sed | sed source file |
| .sgml | SGML source file |
| .sh | sh(1) scripts |
| .shar | archive created by the shar(1) utility |
| .so | Shared library or dynamically loadable object |
| .sql | SQL source |
| .sqml | SQML schema or query program |
| .sty | LaTeX style files |
| .sym | Modula-2 compiled definition modules |
| .tar | archive created by the tar(1) utility |
| .tar.Z | tar(1) archive compressed with compress(1) |
| .tar.bz2 | tar(1) archive compressed with bzip2(1) |
| .tar.gz | tar(1) archive compressed with gzip(1) |
| .taz | tar(1) archive compressed with compress(1) |
| .tcl | tcl source code |
| .tex | TeX or LaTeX source |
| .texi | equivalent to .texinfo |
| .texinfo | Texinfo documentation source |
| .text | text file |
| .tfm | TeX font metric file |
| .tgz | tar archive compressed with gzip(1) |
| .tif | poor man’s .tiff |
| .tiff | Tagged Image File Format |
| .tk | tcl/tk script |
| .tmp | temporary file |
| .tmpl | template files |
| .txt | equivalent to .text |
| .uu | equivalent to .uue |
| .uue | binary file encoded with uuencode(1) |
| .vf | TeX virtual font file |
| .vpl | TeX virtual property list file |
| .w | Silvio Levi’s CWEB |
| .wav | wave sound file |
| .web | Donald Knuth’s WEB |
| .wml | Source file for Web Meta Language |
| .xbm | X11 bitmap source |
| .xcf | GIMP graphic |
| .xml | eXtended Markup Language file |
| .xsl | XSL stylesheet |
| .xpm | X11 pixmap source |
| .xs | Perl xsub file produced by h2xs |
| .y | yacc(1) or bison(1) (parser generator) files |
| .z | File compressed using pack(1) (or an old gzip(1)) |
| .zip | zip(1) archive |
| .zoo | zoo(1) archive |
| ~ | Emacs or patch(1) backup file |
| rc | startup (‘run control’) file, e.g. .newsrc |
