fileutil(3tcl) file utilities fileutil(3tcl)
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NAME
fileutil - Procedures implementing some file utilities
SYNOPSIS
package require Tcl 8
package require fileutil ?1.16?
::fileutil::lexnormalize path
::fileutil::fullnormalize path
::fileutil::test path codes ?msgvar? ?label?
::fileutil::cat (?options? file)...
::fileutil::writeFile ?options? file data
::fileutil::appendToFile ?options? file data
::fileutil::insertIntoFile ?options? file at data
::fileutil::removeFromFile ?options? file at n
::fileutil::replaceInFile ?options? file at n data
::fileutil::updateInPlace ?options? file cmd
::fileutil::fileType filename
::fileutil::find ?basedir ?filtercmd??
::fileutil::findByPattern basedir ?-regexp|-glob? ?--? patterns
::fileutil::foreachLine var filename cmd
::fileutil::grep pattern ?files?
::fileutil::install ?-m mode? source destination
::fileutil::stripN path n
::fileutil::stripPwd path
::fileutil::stripPath prefix path
::fileutil::jail jail path
::fileutil::touch ?-a? ?-c? ?-m? ?-r ref_file? ?-t time? filename ?...?
::fileutil::tempdir
::fileutil::tempdir path
::fileutil::tempdirReset
::fileutil::tempfile ?prefix?
::fileutil::maketempdir ?-prefix str? ?-suffix str? ?-dir str?
::fileutil::relative base dst
::fileutil::relativeUrl base dst
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DESCRIPTION
This package provides implementations of standard unix utilities.
::fileutil::lexnormalize path
This command performs purely lexical normalization on the path
and returns the changed path as its result. Symbolic links in
the path are not resolved.
Examples:
fileutil::lexnormalize /foo/./bar
=> /foo/bar
fileutil::lexnormalize /foo/../bar
=> /bar
::fileutil::fullnormalize path
This command resolves all symbolic links in the path and returns
the changed path as its result. In contrast to the builtin file
normalize this command resolves a symbolic link in the last ele-
ment of the path as well.
::fileutil::test path codes ?msgvar? ?label?
A command for the testing of several properties of a path. The
properties to test for are specified in codes, either as a list
of keywords describing the properties, or as a string where each
letter is a shorthand for a property to test. The recognized
keywords, shorthands, and associated properties are shown in the
list below. The tests are executed in the order given to the
command.
The result of the command is a boolean value. It will be true if
and only if the path passes all the specified tests. In the
case of the path not passing one or more test the first failing
test will leave a message in the variable referenced by msgvar,
if such is specified. The message will be prefixed with label,
if it is specified. Note that the variabled referenced by msg-
var is not touched at all if all the tests pass.
read file readable
write file writable
exists file exists
exec file executable
file file isfile
dir file isdirectory
::fileutil::cat (?options? file)...
A tcl implementation of the UNIX cat command. Returns the con-
tents of the specified file(s). The arguments are files to read,
with interspersed options configuring the process. If there are
problems reading any of the files, an error will occur, and no
data will be returned.
The options accepted are -encoding, -translation, -eofchar, and
--. With the exception of the last all options take a single
value as argument, as specified by the tcl builtin command fcon-
figure. The -- has to be used to terminate option processing be-
fore a file if that file's name begins with a dash.
Each file can have its own set of options coming before it, and
for anything not specified directly the defaults are inherited
from the options of the previous file. The first file inherits
the system default for unspecified options.
::fileutil::writeFile ?options? file data
The command replaces the current contents of the specified file
with data, with the process configured by the options. The com-
mand accepts the same options as ::fileutil::cat. The specifica-
tion of a non-existent file is legal and causes the command to
create the file (and all required but missing directories).
::fileutil::appendToFile ?options? file data
This command is like ::fileutil::writeFile, except that the pre-
vious contents of file are not replaced, but appended to. The
command accepts the same options as ::fileutil::cat
::fileutil::insertIntoFile ?options? file at data
This comment is similar to ::fileutil::appendToFile, except that
the new data is not appended at the end, but inserted at a spec-
ified location within the file. In further contrast this command
has to be given the path to an existing file. It will not create
a missing file, but throw an error instead.
The specified location at has to be an integer number in the
range 0 ... [file size file]. 0 will cause insertion of the new
data before the first character of the existing content, whereas
[file size file] causes insertion after the last character of
the existing content, i.e. appending.
The command accepts the same options as ::fileutil::cat.
::fileutil::removeFromFile ?options? file at n
This command is the complement to ::fileutil::insertIntoFile,
removing n characters from the file, starting at location at.
The specified location at has to be an integer number in the
range 0 ... [file size file] - n. 0 will cause the removal of
the new data to start with the first character of the existing
content, whereas [file size file] - n causes the removal of the
tail of the existing content, i.e. the truncation of the file.
The command accepts the same options as ::fileutil::cat.
::fileutil::replaceInFile ?options? file at n data
This command is a combination of ::fileutil::removeFromFile and
::fileutil::insertIntoFile. It first removes the part of the
contents specified by the arguments at and n, and then inserts
data at the given location, effectively replacing the removed by
content with data. All constraints imposed on at and n by
::fileutil::removeFromFile and ::fileutil::insertIntoFile are
obeyed.
The command accepts the same options as ::fileutil::cat.
::fileutil::updateInPlace ?options? file cmd
This command can be seen as the generic core functionality of
::fileutil::replaceInFile. It first reads the contents of the
specified file, then runs the command prefix cmd with that data
appended to it, and at last writes the result of that invokation
back as the new contents of the file.
If the executed command throws an error the file is not changed.
The command accepts the same options as ::fileutil::cat.
::fileutil::fileType filename
An implementation of the UNIX file command, which uses various
heuristics to guess the type of a file. Returns a list specify-
ing as much type information as can be determined about the
file, from most general (eg, "binary" or "text") to most spe-
cific (eg, "gif"). For example, the return value for a GIF file
would be "binary graphic gif". The command will detect the fol-
lowing types of files: directory, empty, binary, text, script
(with interpreter), executable elf, executable dos, executable
ne, executable pe, graphic gif, graphic jpeg, graphic png,
graphic tiff, graphic bitmap, html, xml (with doctype if avail-
able), message pgp, binary pdf, text ps, text eps, binary grav-
ity_wave_data_frame, compressed bzip, compressed gzip, com-
pressed zip, compressed tar, audio wave, audio mpeg, and link.
It further detects doctools, doctoc, and docidx documentation
files, and tklib diagrams.
::fileutil::find ?basedir ?filtercmd??
An implementation of the unix command find. Adapted from the
Tcler's Wiki. Takes at most two arguments, the path to the di-
rectory to start searching from and a command to use to evaluate
interest in each file. The path defaults to ".", i.e. the cur-
rent directory. The command defaults to the empty string, which
means that all files are of interest. The command takes care not
to lose itself in infinite loops upon encountering circular link
structures. The result of the command is a list containing the
paths to the interesting files.
The filtercmd, if specified, is interpreted as a command prefix
and one argument is added to it, the name of the file or direc-
tory find is currently looking at. Note that this name is not
fully qualified. It has to be joined it with the result of pwd
to get an absolute filename.
The result of filtercmd is a boolean value that indicates if the
current file should be included in the list of interesting
files.
Example:
# find .tcl files
package require fileutil
proc is_tcl {name} {return [string match *.tcl $name]}
set tcl_files [fileutil::find . is_tcl]
::fileutil::findByPattern basedir ?-regexp|-glob? ?--? patterns
This command is based upon the TclX command recursive_glob, ex-
cept that it doesn't allow recursion over more than one direc-
tory at a time. It uses ::fileutil::find internally and is thus
able to and does follow symbolic links, something the TclX com-
mand does not do. First argument is the directory to start the
search in, second argument is a list of patterns. The command
returns a list of all files reachable through basedir whose
names match at least one of the patterns. The options before the
pattern-list determine the style of matching, either regexp or
glob. glob-style matching is the default if no options are
given. Usage of the option -- stops option processing. This al-
lows the use of a leading '-' in the patterns.
::fileutil::foreachLine var filename cmd
The command reads the file filename and executes the script cmd
for every line in the file. During the execution of the script
the variable var is set to the contents of the current line. The
return value of this command is the result of the last invoca-
tion of the script cmd or the empty string if the file was
empty.
::fileutil::grep pattern ?files?
Implementation of grep. Adapted from the Tcler's Wiki. The first
argument defines the pattern to search for. This is followed by
a list of files to search through. The list is optional and
stdin will be used if it is missing. The result of the proce-
dures is a list containing the matches. Each match is a single
element of the list and contains filename, number and contents
of the matching line, separated by a colons.
::fileutil::install ?-m mode? source destination
The install command is similar in functionality to the install
command found on many unix systems, or the shell script distrib-
uted with many source distributions (unix/install-sh in the Tcl
sources, for example). It copies source, which can be either a
file or directory to destination, which should be a directory,
unless source is also a single file. The ?-m? option lets the
user specify a unix-style mode (either octal or symbolic - see
file attributes.
::fileutil::stripN path n
Removes the first n elements from the specified path and returns
the modified path. If n is greater than the number of components
in path an empty string is returned. The number of components in
a given path may be determined by performing llength on the list
returned by file split.
::fileutil::stripPwd path
If, and only if the path is inside of the directory returned by
[pwd] (or the current working directory itself) it is made rela-
tive to that directory. In other words, the current working di-
rectory is stripped from the path. The possibly modified path
is returned as the result of the command. If the current working
directory itself was specified for path the result is the string
".".
::fileutil::stripPath prefix path
If, and only of the path is inside of the directory "prefix" (or
the prefix directory itself) it is made relative to that direc-
tory. In other words, the prefix directory is stripped from the
path. The possibly modified path is returned as the result of
the command. If the prefix directory itself was specified for
path the result is the string ".".
::fileutil::jail jail path
This command ensures that the path is not escaping the directory
jail. It always returns an absolute path derived from path which
is within jail.
If path is an absolute path and already within jail it is re-
turned unmodified.
An absolute path outside of jail is stripped of its root element
and then put into the jail by prefixing it with it. The same
happens if path is relative, except that nothing is stripped of
it. Before adding the jail prefix the path is lexically normal-
ized to prevent the caller from using .. segments in path to es-
cape the jail.
::fileutil::touch ?-a? ?-c? ?-m? ?-r ref_file? ?-t time? filename ?...?
Implementation of touch. Alter the atime and mtime of the speci-
fied files. If -c, do not create files if they do not already
exist. If -r, use the atime and mtime from ref_file. If -t, use
the integer clock value time. It is illegal to specify both -r
and -t. If -a, only change the atime. If -m, only change the
mtime.
This command is not available for Tcl versions less than 8.3.
::fileutil::tempdir
The command returns the path of a directory where the caller can
place temporary files, such as "/tmp" on Unix systems. The algo-
rithm we use to find the correct directory is as follows:
[1] The directory set by an invokation of ::fileutil::tempdir
with an argument. If this is present it is tried exclu-
sively and none of the following item are tried.
[2] The directory named in the TMPDIR environment variable.
[3] The directory named in the TEMP environment variable.
[4] The directory named in the TMP environment variable.
[5] A platform specific location:
Windows
"C:\TEMP", "C:\TMP", "\TEMP", and "\TMP" are tried
in that order.
(classic) Macintosh
The TRASH_FOLDER environment variable is used.
This is most likely not correct.
Unix The directories "/tmp", "/var/tmp", and "/usr/tmp"
are tried in that order.
The algorithm utilized is mainly that used in the Python standard li-
brary. The exception is the first item, the ability to have the search
overridden by a user-specified directory.
::fileutil::tempdir path
In this mode the command sets the path as the first and only di-
rectory to try as a temp. directory. See the previous item for
the use of the set directory. The command returns the empty
string.
::fileutil::tempdirReset
Invoking this command clears the information set by the last
call of [::fileutil::tempdir path]. See the last item too.
::fileutil::tempfile ?prefix?
The command generates a temporary file name suitable for writing
to, and the associated file. The file name will be unique, and
the file will be writable and contained in the appropriate sys-
tem specific temp directory. The name of the file will be re-
turned as the result of the command.
The code was taken from http://wiki.tcl.tk/772, attributed to
Igor Volobouev and anon.
::fileutil::maketempdir ?-prefix str? ?-suffix str? ?-dir str?
The command generates a temporary directory suitable for writing
to. The directory name will be unique, and the directory will
be writable and contained in the appropriate system specific
temp directory. The name of the directory will be returned as
the result of the command.
The three options can used to tweak the behaviour of the com-
mand:
-prefix str
The initial, fixed part of the directory name. Defaults
to tmp if not specified.
-suffix str
The fixed tail of the directory. Defaults to the empty
string if not specified.
-dir str
The directory to place the new directory into. Defaults
to the result of fileutil::tempdir if not specified.
The initial code for this was supplied by Miguel Martinez Lopez
[mailto:aplicacionamedida@gmail.com].
::fileutil::relative base dst
This command takes two directory paths, both either absolute or
relative and computes the path of dst relative to base. This
relative path is returned as the result of the command. As im-
plied in the previous sentence, the command is not able to com-
pute this relationship between the arguments if one of the paths
is absolute and the other relative.
Note: The processing done by this command is purely lexical.
Symbolic links are not taken into account.
::fileutil::relativeUrl base dst
This command takes two file paths, both either absolute or rela-
tive and computes the path of dst relative to base, as seen from
inside of the base. This is the algorithm how a browser resolves
a relative link found in the currently shown file.
The computed relative path is returned as the result of the com-
mand. As implied in the previous sentence, the command is not
able to compute this relationship between the arguments if one
of the paths is absolute and the other relative.
Note: The processing done by this command is purely lexical.
Symbolic links are not taken into account.
WARNINGS AND INCOMPATIBILITIES
1.14.9 In this version fileutil::find's broken system for handling sym-
links was replaced with one working correctly and properly enu-
merating all the legal non-cyclic paths under a base directory.
While correct this means that certain pathological directory hi-
erarchies with cross-linked sym-links will now take about
O(n**2) time to enumerate whereas the original broken code man-
aged O(3tcl) due to its brokenness.
A concrete example and extreme case is the "/sys" hierarchy un-
der Linux where some hundred devices exist under both "/sys/de-
vices" and "/sys/class" with the two sub-hierarchies linking to
the other, generating millions of legal paths to enumerate. The
structure, reduced to three devices, roughly looks like
/sys/class/tty/tty0 --> ../../dev/tty0
/sys/class/tty/tty1 --> ../../dev/tty1
/sys/class/tty/tty2 --> ../../dev/tty1
/sys/dev/tty0/bus
/sys/dev/tty0/subsystem --> ../../class/tty
/sys/dev/tty1/bus
/sys/dev/tty1/subsystem --> ../../class/tty
/sys/dev/tty2/bus
/sys/dev/tty2/subsystem --> ../../class/tty
The command fileutil::find currently has no way to escape this. When
having to handle such a pathological hierarchy It is recommended to
switch to package fileutil::traverse and the same-named command it pro-
vides, and then use the -prefilter option to prevent the traverser from
following symbolic links, like so:
package require fileutil::traverse
proc NoLinks {fileName} {
if {[string equal [file type $fileName] link]} {
return 0
}
return 1
}
fileutil::traverse T /sys/devices -prefilter NoLinks
T foreach p {
puts $p
}
T destroy
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category fileutil
of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
also report any ideas for enhancements you may have for either package
and/or documentation.
When proposing code changes, please provide unified diffs, i.e the out-
put of diff -u.
Note further that attachments are strongly preferred over inlined
patches. Attachments can be made by going to the Edit form of the
ticket immediately after its creation, and then using the left-most
button in the secondary navigation bar.
KEYWORDS
cat, file utilities, grep, temp file, test, touch, type
CATEGORY
Programming tools
tcllib 1.16 fileutil(3tcl)