'\" '\" Copyright (c) 1995-1996 Sun Microsystems, Inc. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" RCS: @(#) $Id: filename.n,v 1.1.1.2 2009/03/23 15:10:43 duncan Exp $ '\" '\" The definitions below are for supplemental macros used in Tcl/Tk '\" manual entries. '\" '\" .AP type name in/out ?indent? '\" Start paragraph describing an argument to a library procedure. '\" type is type of argument (int, etc.), in/out is either "in", "out", '\" or "in/out" to describe whether procedure reads or modifies arg, '\" and indent is equivalent to second arg of .IP (shouldn't ever be '\" needed; use .AS below instead) '\" '\" .AS ?type? ?name? '\" Give maximum sizes of arguments for setting tab stops. Type and '\" name are examples of largest possible arguments that will be passed '\" to .AP later. If args are omitted, default tab stops are used. '\" '\" .BS '\" Start box enclosure. From here until next .BE, everything will be '\" enclosed in one large box. '\" '\" .BE '\" End of box enclosure. '\" '\" .CS '\" Begin code excerpt. '\" '\" .CE '\" End code excerpt. '\" '\" .VS ?version? ?br? '\" Begin vertical sidebar, for use in marking newly-changed parts '\" of man pages. The first argument is ignored and used for recording '\" the version when the .VS was added, so that the sidebars can be '\" found and removed when they reach a certain age. If another argument '\" is present, then a line break is forced before starting the sidebar. '\" '\" .VE '\" End of vertical sidebar. '\" '\" .DS '\" Begin an indented unfilled display. '\" '\" .DE '\" End of indented unfilled display. '\" '\" .SO '\" Start of list of standard options for a Tk widget. The '\" options follow on successive lines, in four columns separated '\" by tabs. '\" '\" .SE '\" End of list of standard options for a Tk widget. '\" '\" .OP cmdName dbName dbClass '\" Start of description of a specific option. cmdName gives the '\" option's name as specified in the class command, dbName gives '\" the option's name in the option database, and dbClass gives '\" the option's class in the option database. '\" '\" .UL arg1 arg2 '\" Print arg1 underlined, then print arg2 normally. '\" '\" RCS: @(#) $Id: man.macros,v 1.1.1.1 2007/07/10 15:04:23 duncan Exp $ '\" '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. .if t .wh -1.3i ^B .nr ^l \n(.l .ad b '\" # Start an argument description .de AP .ie !"\\$4"" .TP \\$4 .el \{\ . ie !"\\$2"" .TP \\n()Cu . el .TP 15 .\} .ta \\n()Au \\n()Bu .ie !"\\$3"" \{\ \&\\$1 \\fI\\$2\\fP (\\$3) .\".b .\} .el \{\ .br .ie !"\\$2"" \{\ \&\\$1 \\fI\\$2\\fP .\} .el \{\ \&\\fI\\$1\\fP .\} .\} .. '\" # define tabbing values for .AP .de AS .nr )A 10n .if !"\\$1"" .nr )A \\w'\\$1'u+3n .nr )B \\n()Au+15n .\" .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n .nr )C \\n()Bu+\\w'(in/out)'u+2n .. .AS Tcl_Interp Tcl_CreateInterp in/out '\" # BS - start boxed text '\" # ^y = starting y location '\" # ^b = 1 .de BS .br .mk ^y .nr ^b 1u .if n .nf .if n .ti 0 .if n \l'\\n(.lu\(ul' .if n .fi .. '\" # BE - end boxed text (draw box now) .de BE .nf .ti 0 .mk ^t .ie n \l'\\n(^lu\(ul' .el \{\ .\" Draw four-sided box normally, but don't draw top of .\" box if the box started on an earlier page. .ie !\\n(^b-1 \{\ \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .el \}\ \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .\} .fi .br .nr ^b 0 .. '\" # VS - start vertical sidebar '\" # ^Y = starting y location '\" # ^v = 1 (for troff; for nroff this doesn't matter) .de VS .if !"\\$2"" .br .mk ^Y .ie n 'mc \s12\(br\s0 .el .nr ^v 1u .. '\" # VE - end of vertical sidebar .de VE .ie n 'mc .el \{\ .ev 2 .nf .ti 0 .mk ^t \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' .sp -1 .fi .ev .\} .nr ^v 0 .. '\" # Special macro to handle page bottom: finish off current '\" # box/sidebar if in box/sidebar mode, then invoked standard '\" # page bottom macro. .de ^B .ev 2 'ti 0 'nf .mk ^t .if \\n(^b \{\ .\" Draw three-sided box if this is the box's first page, .\" draw two sides but no top otherwise. .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .\} .if \\n(^v \{\ .nr ^x \\n(^tu+1v-\\n(^Yu \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c .\} .bp 'fi .ev .if \\n(^b \{\ .mk ^y .nr ^b 2 .\} .if \\n(^v \{\ .mk ^Y .\} .. '\" # DS - begin display .de DS .RS .nf .sp .. '\" # DE - end display .de DE .fi .RE .sp .. '\" # SO - start of list of standard options .de SO .SH "STANDARD OPTIONS" .LP .nf .ta 5.5c 11c .ft B .. '\" # SE - end of list of standard options .de SE .fi .ft R .LP See the \\fBoptions\\fR manual entry for details on the standard options. .. '\" # OP - start of full description for a single option .de OP .LP .nf .ta 4c Command-Line Name: \\fB\\$1\\fR Database Name: \\fB\\$2\\fR Database Class: \\fB\\$3\\fR .fi .IP .. '\" # CS - begin code excerpt .de CS .RS .nf .ta .25i .5i .75i 1i .. '\" # CE - end code excerpt .de CE .fi .RE .. .de UL \\$1\l'|0\(ul'\\$2 .. .TH filename n 7.5 Tcl "Tcl Built-In Commands" .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME filename \- File name conventions supported by Tcl commands .BE .SH INTRODUCTION .PP All Tcl commands and C procedures that take file names as arguments expect the file names to be in one of three forms, depending on the current platform. On each platform, Tcl supports file names in the standard forms(s) for that platform. In addition, on all platforms, Tcl supports a Unix-like syntax intended to provide a convenient way of constructing simple file names. However, scripts that are intended to be portable should not assume a particular form for file names. Instead, portable scripts must use the \fBfile split\fR and \fBfile join\fR commands to manipulate file names (see the \fBfile\fR manual entry for more details). .SH "PATH TYPES" .PP File names are grouped into three general types based on the starting point for the path used to specify the file: absolute, relative, and volume-relative. Absolute names are completely qualified, giving a path to the file relative to a particular volume and the root directory on that volume. Relative names are unqualified, giving a path to the file relative to the current working directory. Volume-relative names are partially qualified, either giving the path relative to the root directory on the current volume, or relative to the current directory of the specified volume. The \fBfile pathtype\fR command can be used to determine the type of a given path. .SH "PATH SYNTAX" .PP The rules for native names depend on the value reported in the Tcl array element \fBtcl_platform(platform)\fR: .TP 10 \fBmac\fR On Apple Macintosh systems, Tcl supports two forms of path names. The normal Mac style names use colons as path separators. Paths may be relative or absolute, and file names may contain any character other than colon. A leading colon causes the rest of the path to be interpreted relative to the current directory. If a path contains a colon that is not at the beginning, then the path is interpreted as an absolute path. Sequences of two or more colons anywhere in the path are used to construct relative paths where \fB::\fR refers to the parent of the current directory, \fB:::\fR refers to the parent of the parent, and so forth. .RS .PP In addition to Macintosh style names, Tcl also supports a subset of Unix-like names. If a path contains no colons, then it is interpreted like a Unix path. Slash is used as the path separator. The file name \fB\&.\fR refers to the current directory, and \fB\&..\fR refers to the parent of the current directory. However, some names like \fB/\fR or \fB/..\fR have no mapping, and are interpreted as Macintosh names. In general, commands that generate file names will return Macintosh style names, but commands that accept file names will take both Macintosh and Unix-style names. .PP The following examples illustrate various forms of path names: .TP 15 \fB:\fR Relative path to the current folder. .TP 15 \fBMyFile\fR Relative path to a file named \fBMyFile\fR in the current folder. .TP 15 \fBMyDisk:MyFile\fR Absolute path to a file named \fBMyFile\fR on the device named \fBMyDisk\fR. .TP 15 \fB:MyDir:MyFile\fR Relative path to a file name \fBMyFile\fR in a folder named \fBMyDir\fR in the current folder. .TP 15 \fB::MyFile\fR Relative path to a file named \fBMyFile\fR in the folder above the current folder. .TP 15 \fB:::MyFile\fR Relative path to a file named \fBMyFile\fR in the folder two levels above the current folder. .TP 15 \fB/MyDisk/MyFile\fR Absolute path to a file named \fBMyFile\fR on the device named \fBMyDisk\fR. .TP 15 \fB\&../MyFile\fR Relative path to a file named \fBMyFile\fR in the folder above the current folder. .RE .TP \fBunix\fR On Unix platforms, Tcl uses path names where the components are separated by slashes. Path names may be relative or absolute, and file names may contain any character other than slash. The file names \fB\&.\fR and \fB\&..\fR are special and refer to the current directory and the parent of the current directory respectively. Multiple adjacent slash characters are interpreted as a single separator. The following examples illustrate various forms of path names: .RS .TP 15 \fB/\fR Absolute path to the root directory. .TP 15 \fB/etc/passwd\fR Absolute path to the file named \fBpasswd\fR in the directory \fBetc\fR in the root directory. .TP 15 \fB\&.\fR Relative path to the current directory. .TP 15 \fBfoo\fR Relative path to the file \fBfoo\fR in the current directory. .TP 15 \fBfoo/bar\fR Relative path to the file \fBbar\fR in the directory \fBfoo\fR in the current directory. .TP 15 \fB\&../foo\fR Relative path to the file \fBfoo\fR in the directory above the current directory. .RE .TP \fBwindows\fR On Microsoft Windows platforms, Tcl supports both drive-relative and UNC style names. Both \fB/\fR and \fB\e\fR may be used as directory separators in either type of name. Drive-relative names consist of an optional drive specifier followed by an absolute or relative path. UNC paths follow the general form \fB\e\eservername\esharename\epath\efile\fR, but must at the very least contain the server and share components, i.e. \fB\e\eservername\esharename\fR. In both forms, the file names \fB.\fR and \fB..\fR are special and refer to the current directory and the parent of the current directory respectively. The following examples illustrate various forms of path names: .RS .TP 15 \fB\&\e\eHost\eshare/file\fR Absolute UNC path to a file called \fBfile\fR in the root directory of the export point \fBshare\fR on the host \fBHost\fR. Note that repeated use of \fBfile dirname\fR on this path will give \fB//Host/share\fR, and will never give just \fB//Host\fR. .TP 15 \fBc:foo\fR Volume-relative path to a file \fBfoo\fR in the current directory on drive \fBc\fR. .TP 15 \fBc:/foo\fR Absolute path to a file \fBfoo\fR in the root directory of drive \fBc\fR. .TP 15 \fBfoo\ebar\fR Relative path to a file \fBbar\fR in the \fBfoo\fR directory in the current directory on the current volume. .TP 15 \fB\&\efoo\fR Volume-relative path to a file \fBfoo\fR in the root directory of the current volume. .TP 15 \fB\&\e\efoo\fR Volume-relative path to a file \fBfoo\fR in the root directory of the current volume. This is not a valid UNC path, so the assumption is that the extra backslashes are superfluous. .RE .SH "TILDE SUBSTITUTION" .PP In addition to the file name rules described above, Tcl also supports \fIcsh\fR-style tilde substitution. If a file name starts with a tilde, then the file name will be interpreted as if the first element is replaced with the location of the home directory for the given user. If the tilde is followed immediately by a separator, then the \fB$HOME\fR environment variable is substituted. Otherwise the characters between the tilde and the next separator are taken as a user name, which is used to retrieve the user's home directory for substitution. .PP The Macintosh and Windows platforms do not support tilde substitution when a user name follows the tilde. On these platforms, attempts to use a tilde followed by a user name will generate an error that the user does not exist when Tcl attempts to interpret that part of the path or otherwise access the file. The behaviour of these paths when not trying to interpret them is the same as on Unix. File names that have a tilde without a user name will be correctly substituted using the \fB$HOME\fR environment variable, just like for Unix. .SH "PORTABILITY ISSUES" .PP Not all file systems are case sensitive, so scripts should avoid code that depends on the case of characters in a file name. In addition, the character sets allowed on different devices may differ, so scripts should choose file names that do not contain special characters like: \fB<>:"/\e|\fR. The safest approach is to use names consisting of alphanumeric characters only. Also Windows 3.1 only supports file names with a root of no more than 8 characters and an extension of no more than 3 characters. .PP On Windows platforms there are file and path length restrictions. Complete paths or filenames longer than about 260 characters will lead to errors in most file operations. .PP Another Windows peculiarity is that any number of trailing dots '.' in filenames are totally ignored, so, for example, attempts to create a file or directory with a name "foo." will result in the creation of a file/directory with name "foo". This fact is reflected in the results of 'file normalize'. Furthermore, a file name consisting only of dots '.........' or dots with trailing characters '.....abc' is illegal. .SH KEYWORDS current directory, absolute file name, relative file name, volume-relative file name, portability .SH "SEE ALSO" file(n), glob(n)