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Table of Contents
6.3 File and Directory Functions
These file and directory functions as well as supplementary functions are presented in the following sections:
- 6.3.1 COPY … TO …
- 6.3.2 DFREE
- 6.3.3 EXIST
- 6.3.4 ISDIR
- 6.3.5 KILL
- 6.3.6 RMDIR
- 6.3.7 LINK
- 6.3.8 MKDIR
- 6.3.9 MOVE … TO …
- 6.3.10 MOVE … KILL
- 6.3.11 DIR
- 6.3.12 RDIR
- 6.3.13 Digression 1 - Determining the size of a directory
- 6.3.14 Digression 2 - Creating a file
- 6.3.15 Digression 3 - Copying a directory
6.3.1 COPY ... TO ...
COPY SourcePath TO DestinationPath
- This instruction copies a file from the source SourcePath to the destination DestinationPath.
- The destination path does not have to have the same (base) name as the source path.
- Note that you cannot copy directories recursively with this instruction!
- An error (error number 38) is triggered if the target file already exists.
- This instruction internally uses the functions, OPEN, READ, WRITE and CLOSE, which is why all the associated error messages can also occur and the timestamps do not match those of the original file.
Example 1:
Public sScriptPath As String Public sTempScriptPath As String Public Sub Form_Open() sScriptPath = "./data/test_script.sh" sTempScriptPath = Temp(File.BaseName(sScriptPath)) Copy sScriptPath To sTempScriptPath Chmod sTempScriptPath To "r-xr-x---" … End
A bash script is copied from the data folder inside the project folder into a temporary file /tmp/gambas.1000/5503/test_script.tmp. This is necessary here because only then are the permissions set so that the script becomes executable for the user and the group.
Example 2:
Public Sub btnCopyFile_Click() ' Based on an idea by Willy Raets Dim sSourcePath, sDestinationPath, sFilename As String sSourcePath = User.Home &/ "DW" sDestinationPath = User.Home &/ "GB3BUCH" sFileName = "dokuwiki_syntax.txt" ' Check whether the file to be copied exists. If Exist(sSourcePath &/ sFileName) Then ' Now check if copyto directory exists If Not Exist(sDestinationPath) Then Try Mkdir sDestinationPath If Error Then Message.Error("Error! " & Error.Text) Return Endif Endif ' Now check if copyto file exists If Not (Exist(sDestinationPath & sFileName)) Then Try Copy sSourcePath &/ sFileName To sDestinationPath &/ sFileName Else ' If Exists first remove old file then copy new file Kill sDestinationPath &/ sFileName Try Copy sSourcePath &/ sFileName To sDestinationPath &/ sFileName If Error Then Message.Error("Error! " & Error.Text) Return Endif Endif Else Message.Error("File not exist: " & sFileName) Return Endif Message.Info("File '" & sFileName & "' successfully copied!") End
The text file dokuwiki_syntax.txt from the directory /home/hans/DW is copied to the directory /home/hans/GB3BUCH. Various checks and messages ensure successful copying of the specified file.
6.3.2 DFREE
DFree( sPath AS String ) AS Long
Returns the size of the free space (in bytes) of the mass storage on which the directory sPath is located. Always compare the result with a comparison value of long integer data type, as storage media can have more than 2^32 bytes capacity.
Example 1:
Dim ilFree As Long ilFree = DFree(User.Home &/ "DW") ' 346.218.151.936 Print Round(ilFree / 10 ^ 9, -3) & " GB" ' 346.218 GB
Interpret the result to mean that there is about 346 GB of free space left on the hard disk in the author's PC.
Example 2:
Print DFree(“/media/hans/USB-STICK“)
To determine the size of the free space on the connected USB stick in the Gambas console.
6.3.3 EXIST
Exist( sPath ) As Boolean
Indicates whether a file or directory with the path sPath exists.
Example:
If Not Exist(User.Home &/ "Destination") Then MkDir(User.Home &/ "Destination") Endif
The directory 'Destination' is only created with the specified path if it does not exist.
6.3.4 ISDIR
IsDir ( sPath AS String ) AS Boolean
Returns True if the path specification points to a directory. If the path sPath does not exist or if the path does not point to a directory, then this function returns False.
Example:
Dim sPath As String sPath = User.Home &/ "test33" If Not Exist(sPath) Then Mkdir sPath Print "Is Directory? = "; IsDir(sPath) ' TRUE sPath = User.Home &/ "test34" If Not Exist(sPath) Then File.Save(sPath, "CONTENT") Print "Is Directory? = "; IsDir(sPath) ' FALSE
In a directory, no file can have the same name as a directory. Hence the change from test33 to test34.
6.3.5 KILL
KILL FilePath
Deletes an existing file whose (absolute) path is in the string FilePath.
Example:
Dim sSourcePath, sDestinationPath As String sSourcePath = "./css" &/ fCSSFileName sDestinationPath = sWorkDirectory &/ "css" &/ fCSSFileName If Stat(sSourcePath).LastChange > Stat(sDestinationPath).LastChange Then Try Kill sDestinationPath Try Copy sSourcePath To sDestinationPath Endif
If a more recent css file exists in the 'css' directory in the project directory, then the original css file is deleted and the current css file is copied to the existing working directory.
On the other hand, if you want to delete a directory, use the following RMDIR statement.
6.3.6 RMDIR
RMDIR DirectoryPath
Deletes the directory specified by DirectoryPath, but it must be empty!
Example:
If RDir(DirectoryPath).Count > 0 Then Message.Warning("The specified directory is not empty and therefore cannot be deleted.") Return Else Try Rmdir DirectoryPath Message.Info("The specified directory was successfully deleted!") Endif
First it is checked whether the specified directory is empty. If the directory is empty, it is deleted - otherwise a warning is issued and the deletion process is aborted.
Note: For a good alternative, use the function Shell.RmDir( DirectoryPath As String) from the component gb.util. It removes the specified directory by removing its entire contents recursively!
6.3.7 LINK
LINK sOriginalPath TO sSoftLinkPath
Creates a symbolic link (softlink) with path sSoftLinkPath pointing to the target file or directory sOriginalPath.
Example:
Dim sSoftLinkPath, sOriginalPath As String sOriginalPath = "/home/hans/DW/0_DW_Convert/librewriter2dokuwiki.gambas" sSoftLinkPath = "/home/hans/Schreibtisch/Formatting_DokuWiki_Tables" If Not Exist(sSoftLinkPath) Then Try Link sOriginalPath To sSoftLinkPath If Error Then Message.Error(Error.Text) Endif
A permanent link is created on the desktop with the name 'Formatting_DokuWiki_Tables' to a Gambas executable file.
6.3.8 MKDIR
MKDIR DirectoryPath
Creates the directory specified by DirectoryPath. By default, the MKDIR command creates a directory with the rights 0755. If you need other rights, set them with the CHMOD instruction. If at least one parent directory of the specified path does not exist, an error is triggered.
Example:
Dim sDirectoryPath As String Dim FileInfo As Stat sDirectoryPath = User.Home &/ "Test18" If Not Exist(sDirectoryPath) Then Mkdir sDirectoryPath FileInfo = Stat(sDirectoryPath) Print Oct(FileInfo.Mode) ' Output: 755 Endif
Only if the specified directory does not exist, it will be created. With the value of the Mode property of the Stat object FileInfo, you can display the rights of the created directory in a suitable format.
Note: As an alternative, use the Shell.MkDir( DirectoryPath As String) function from the gb.util component, as a directory with DirectoryPath as the directory path and all its parent (parent) directories will be created.
6.3.9 MOVE ... TO ...
MOVE OldName TO NewName
Renames or moves a file or directory. Oldname and NewName can be in different directories - but must be on the same device!
Alternatively, use the function Move(Source As String, Destination As String) with Source as the path of the source file and Destination as the destination path. This function moves a file or directory - even if they are on different devices.
Example 1:
If you want to move a file - regardless of its location - proceed like this:
Try Move OldFilePath To NewFilePath If Error Then Try Copy OldFilePath To NewFilePath If Not Error Then Kill OldFilePath Endif
A file A with the path OldFilePath is moved. If an error occurs, the file A with the path OldFilePath is copied to NewFilePath. If no error occurs, the file A is finally deleted.
Example 2:
Public Sub RenameDirectory(OldDirPath As String, NewDirPath As String) Try Move OldDirPath To NewDirPath If Error Then Message.Error("Error when renaming." & gb.Lf & Error.Text & " !") Return Endif End Public Sub btnRenameDirectory_Click() RenameDirectory(User.Home &/ "Test18", User.Home &/ "Test19") End
The first time the procedure is called, the directory Test18 is renamed to Test19. With each subsequent call, an error is triggered and the error message 'Error when renaming. File already exists!' is displayed.
Example 3:
Public Sub MoveDirectory(OldDirPath As String, NewDirPath As String) Try Move OldDirPath To NewDirPath If Error Then Message.Error("Error when moving." & gb.Lf & Error.Text & " !") Print Error.Text Return Endif End Public Sub btnMoveDirectory_Click() MoveDirectory(User.Home &/ "Test18", User.Home &/ "TWX" &/ "Test18") End
The first time the procedure is called, the directory Test18 is moved to the existing directory TWX. With each subsequent call, an error is triggered and the error message 'Error when renaming. File already exists!' is displayed.
6.3.10 MOVE ... KILL
MOVE OldName KILL NewName MOVE OldName DOWNTO NewName ' Considered obsolete
Renames or moves a file or directory, deleting the target file first, and the two operations are atomic. OldName and NewName can be in different directories but must be on the same device. Normally, moving an existing file will trigger the 'file already exists' error. In this case, the kill instruction acts like an option that first deletes the file existing in the target and only then moves the file.
The function replaces the MOVE OldName DOWNTO NewName function chain, which is considered obsolete.
Example:
Public Sub btnMoveKill_Click() Dim sSourcePath, sDestinationPath, sFilename As String sSourcePath = User.Home &/ "DW" sDestinationPath = User.Home &/ "GB3BUCH" sFileName = "dokuwiki_syntax.txt" ' Check whether the file to be moved exists. If Exist(sSourcePath &/ sFileName) Then ' Now check if moveto directory exists If Not Exist(sDestinationPath) Then Try Mkdir sDestinationPath If Error Then Message.Error("Error! " & Error.Text) Return Endif Endif ' Now the file is moved … Move sSourcePath &/ sFileName Kill sDestinationPath &/ sFileName Else Message.Error("File not exist: " & sFileName) Return Endif Message.Info("File '" & sFileName & "' successfully moved!") End
Variant:
Public Sub btnMoveKill_Click() Dim sSourcePath, sDestinationPath, sFilename As String sSourcePath = User.Home &/ "DW" sDestinationPath = User.Home &/ "GB3BUCH" sFileName = "dokuwiki_syntax.txt" Move sSourcePath &/ sFileName Kill sDestinationPath &/ sFileName Message.Info("File '" & sFileName & "' successfully moved!") Catch Message.Error(Error.Text) End
The file 'dokuwiki_syntax.txt is moved after both variants. If a file with the same name already exists in the target directory, it will be (automatically) deleted beforehand - without generating an error.
6.3.11 DIR
ArrayOfFilenames = Dir ( sDirectory AS String [ , Pattern AS String , Filter AS Integer ] ) AS String[]
The function returns a string array containing only the names of the files and directories in the specified directory sDirectory that match the pattern and filter. You must assemble the file path from the file or directory names and the sDirectory parameter.
- Pattern (optional) can contain the same generic characters as the LIKE operator. If no pattern is specified, then the name of each file and directory found will be returned.
- filter (optional) specifies whether only the names of files or only of directories or both are returned. If no filter is specified, the names of all files and directories in the specified directory that match the pattern are returned.
The filter can be one of the following constants:
- gb.file to return only files.
- gb.Directory to return only directory names,
- gb.File + gb.Directory to return both.
By specifying the pattern and filter appropriately, it is possible, for example, to search specifically for a single file or for a particular (subset) of all files in the specified base directory.
Example 1:
[1] Public Sub ScanDirectory() [2] [3] Dim sDirectoryPath, sPattern, sDirFileName As String [4] Dim sFilter As Integer [5] Dim bMode, bSorted As Boolean [6] [7] sDirectoryPath = User.Home &/ "BildTon" [8] sPattern = "[^0-9P]*.{png,jpg,gif}" [9] sFilter = gb.File ' gb.Directory | gb.File + gb.Directory [10] bSorted = True [11] bMode = gb.Ascent ' gb.Descent | gb.Ascent [12] [13] If bSorted Then [14] If Dir(sDirectoryPath, sPattern, sFilter).Sort(bMode).Count = 0 Then [15] Message.Info("The searched set is empty ...") [16] Return [17] Else [18] For Each sDirFileName In Dir(sDirectoryPath, sPattern, sFilter).Sort(bMode) [19] Print sDirFileName [20] Next [21] Endif [22] Else [23] If Dir(sDirectoryPath, sPattern, sFilter).Count = 0 Then [24] Message.Info("The searched set is empty ...") [25] Return [26] Else [27] For Each sDirFileName In Dir(sDirectoryPath, sPattern, sFilter) [28] Print sDirFileName [29] Next [30] Endif [31] Endif [32] [33] End [34] [35] Public Sub btnScanDirectory_Click() [36] ScanDirectory() [37] End
With the help of the procedure ScanDirectory(), you can have the set of search results output in the console after specifying the directory, the pattern, the filter, the sorting and the sorting order (lines 7 to 11).
The pattern in example 1 is chosen so that only files with the extension png, jpg and gif are in the result set - but their names do not begin with a digit from the set [0-7] or with a P. However, you can also process the results further in lines 19 and 28. It would be conceivable to store all paths of the (image) files of the result set in a string array.
In the following examples, the (base) directory, the pattern, the filter, the sorting and the sorting order are changed and the results are commented.
Example 2:
sDirectoryPath = User.Home sPattern = "[^.]*.txt" sFilter = gb.File bSorted = False bMode = gb.Ascent
Only non-hidden files with the extension .txt in the home directory are displayed. The result set is not sorted.
Example 3:
sDirectoryPath = User.Home sPattern = ".[^A-Z]*" sFilter = gb.Directory bSorted = True bMode = gb.Ascent
Only hidden directories in the home directory that do not begin with a capital letter are listed. The result set is sorted.
6.3.12 RDIR
ArrayOfFilenames = RDir ( BaseDirectory AS String [ , Pattern AS String , Filter AS Integer , FollowLink AS Boolean ] ) AS String[]
Returns a string array containing the names of the files and directories in the specified base directory and its subdirectories that match the pattern and filter. The notes on the pattern and filter for the DIR function apply. If the optional parameter FollowLink is TRUE, symbolic links to directories are followed. Otherwise they are processed like normal files.
Example:
[1] Public Sub ScanDirectoryR() [2] [3] Dim sDirectoryPath, sPattern, sDirFileName As String [4] Dim sFilter As Integer [5] Dim bMode, bSorted As Boolean [6] [7] sDirectoryPath = User.Home &/ "ImageSound" [8] sPattern = "*fractal_0.png" [9] sFilter = gb.File [10] bSorted = False [11] bMode = gb.Ascent [12] [13] If bSorted Then [14] If RDir(sDirectoryPath, sPattern, sFilter).Sort(bMode).Count = 0 Then [15] Message.Info("The searched set is empty ...") [16] Return [17] Else [18] For Each sDirFileName In RDir(sDirectoryPath, sPattern, sFilter).Sort(bMode) [19] Print sDirFileName [20] Next [21] Endif [22] Else [23] If RDir(sDirectoryPath, sPattern, sFilter).Count = 0 Then [24] Message.Info("The searched set is empty ...") [25] Return [26] Else [27] For Each sDirFileName In RDir(sDirectoryPath, sPattern, sFilter) [28] Print sDirFileName [29] Next [30] Endif [31] Endif [32] [33] End [34] [35] Public Sub btnScanDirectoryR_Click() [36] [37] ScanDirectoryR() [38] [39] End
The returned file paths are relative to the searched directory. However, the pattern always corresponds to the full relative path, not just the file name! This is not only reflected in the pattern sPattern = “*fractal_0.png”, but also in the result of the scan: Fractals/fractal_0.png with the specification of the applicable directory. The same applies to the recursive search in the directory tree: choose the pattern and the filter with care.
6.3.13 Excursus 1 - Determining the size of a directory
1st variant - shell instruction
Dim ilSourceSize As Long Dim sSource, sResult, sProjectFolder As String sProjectFolder = "GambasBookProjects" sDestination = "/media/hans/DW_4GB" &/ sProjectFolder sSource = User.Home &/ sProjectFolder Exec ["du", "-sb", sSource] To sResult ilSourceSize = CLong(Split(sResult, "\t")[0]) Print ilSourceSize
2nd variant
Public Function GetDirSize(sDir As String) As Long ' Coding and adaptation of Tony Morehen and Fabien Bodard Dim sFile As String Dim sPath As String Dim hStat As Stat Dim iSize As Long For Each sFile In Dir(sDir) sPath = sDir &/ sFile hStat = Stat(sPath) With hStat If .Type = gb.Directory Then iSize += GetDirSize(sPath) ' Recursion! Endif iSize += .Size End With Next Return iSize End Public Sub btnGetDirSize_Click() Dim ilDirSize As Long Try ilDirSize = GetDirSize(User.Home &/ "GambasBookProjects") If Error Then Message.Error(Error.Text) Print ilDirSize End
6.3.14 Digression 2 - Create file
File.Save(sFilePath, "") File.Save(sFilePath, sContent)
The statements create an empty file with the specified (absolute) file path sFilePath or a file with the content sContent. No error is raised if the file already exists, because then its content is overwritten!
Private Sub CreateTextFiles(sPathDir As String, iNumber As String) Dim sFileName As String Dim i As Integer For i = 1 To iNumber sFileName = Hex$(Rand(0, 2 ^ 32 - 1)) ' Random file name If Not Exist(sPathDir &/ sFileName & ".txt") Then File.Save(sPathDir &/ sFileName & ".txt", "Text line 1.\nText line 2.") Endif Next End
The procedure CreateTextFiles(…) creates a given number (iNumber) of text files - with content - with the specified (absolute) file paths. The (base) file name is a random string.
6.3.15 Digression 3 - Copy Directory
The task is to copy a directory - with contents:
Public Sub CopyDir(Source As String, Destination As String) Dim sFile As String If IsDir(Source) Then If Not Exist(Destination) Then Mkdir Destination For Each sFile In Dir(Source) If Not Exist(Destination &/ sFile) Then CopyDir(Source &/ sFile, Destination &/ sFile) ' Recursion Wait Endif Next Else If Not Exist(Destination) Then Try Copy Source To Destination If Error Then Message.Error(Error.Text) Return Wait Endif Endif End Public Sub btnBackup_Click() CopyDir(User.Home &/ "GambasBookProjects", "/media/hans/DW_4GB" &/ "GambasBookProjects") Print "DONE!" End
k6/k6.3/start.txt · Last modified: 16.01.2022 (external edit)
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