--- rexxpub: defaults: rony.yaml logo: oorexx --- . slide cover # About Storing Files: Where and How? . subtitle **Source directory, current directory, home directory, temporary directory …** . cover-art . picture img/330_Paths_V03/p01-diagram-7.png # About Locations For Storing Files, 1 . after steps - About *directories* (synonym: *folders*) - Can be nested (*directory/folder* in a *directory/folder* …) - *Root directory* has the symbol "`/`" (Unix) or "`\`" (Windows) - Windows has the notion of a *drive*, an alphabetic letter followed by a colon, e.g. "`C:`" . after - A *drive* may be prepended to the directory, e.g. to the *root directory*: "`C:\`" - A `PATH` is the sequence of *directories* (*folders*) to traverse to arrive at the storage location of a file - Each *directory* (*folder*) gets separated with the letter "`/`" (Unix) or "`\`" (Windows) - Windows examples for *absolute* (starts with the *root directory/folder*) and *relative paths* [`C:\Users\JohnDoe\Documents\someFile1.png` (*absolute path*)]{.fragment .afterPrevious} [`Documents\someFile2.png` (*relative path*: relative to *current directory/folder*)]{.fragment .afterPrevious} - Unix examples for *absolute* and *relative paths* [`/Users/MaryDoe/Documents/someFile1.png` (*absolute path*)]{.fragment .afterPrevious} [`Documents/someFile2.png` (*relative path*: relative to *current directory/folder*)]{.fragment .afterPrevious} . slide reference="Cf. rexxref.pdf (2.18. PARSE, 7.4.31. FILESPEC)" # Source Directory . after steps - The directory where the Rexx program is stored - Can be retrieved from Rexx using the `PARSE SOURCE` keyword statement . after ```rexx PARSE SOURCE opsys invocationType pathToRexxProgram ``` - `opsys` refers to the operating system, e.g. "`Windows`", "`Darwin`" (Apple), "`Linux`", … - `invocationType` is one of "`COMMAND`", "`FUNCTION`", "`SUBROUTINE`", "`METHOD`", "`REQUIRES`" - `pathToRexxProgram` is the fully qualified path to the Rexx program, e.g. [`C:\Users\JohnDoe\programs\someProgram.rex` (absolute path, Windows)]{.fragment .afterPrevious} [`/Users/MaryDoe/programs/someProgram.rex` (absolute path, Unix)]{.fragment .afterPrevious} - `FILESPEC()`-BIF (built-in-function) allows to retrieve different parts of a path [e.g. `FILESPEC('location', pathToRexxProgram)` yields for the above two examples:]{.fragment} [`C:\Users\JohnDoe\programs\` (Windows example location)]{.fragment .afterPrevious} [`/Users/MaryDoe/programs/` (Unix example location)]{.fragment .afterPrevious} . slide reference="Cf. rexxref.pdf (7.4.28. DIRECTORY)" # Current Directory . steps each=after - The directory (folder) where the Rexx program executes - Used for looking up additional programs and files without a path - Can be changed arbitrarily while the program executes . click - `directory(optionalNewDir`)-BIF (built-in-function) - Returns the full path to the current directory - If argument `optionalNewDir` supplied, changes the current directory to it . click - Example: . after ```rexx say directory() -- returns path to current directory oldDir=directory("..") -- changes to parent directory/folder ("."=current, ".."=parent directory/folder) say directory() -- returns path to current directory ``` . columns 7 5 . click Output Windows, assuming current directory is \ `C:\Users\MaryDoe\temp`: . next column . click Output Unix, assuming current directory is \ `/Users/JohnDoe/temp`: . end columns . columns 7 5 . after ```output C:\Users\MaryDoe\temp C:\Users\MaryDoe ``` . next column . after ```output /Users/JohnDoe/temp /Users/JohnDoe ``` . end columns . slide reference="Cf. rexxref.pdf (7.4.71. VALUE)" # Home Directory . after - The directory (folder) where all files and directories/folders of a user reside . after - User usually has all permissions for all directories/folders and files therein . click - Operating system defines an environment variable that contains the path . after - Environment variable (Windows): "`USERPROFILE`" . after - Environment variable (UNIX): "`HOME`" . click - Use the `value()`-BIF (built-in-function) to retrieve the environment variable's value, e.g. . after - Example Windows: ```rexx homeDir=value('USERPROFILE', ,'ENVIRONMENT') -- maybe: "C:\Users\JohnDoe" ``` . after - Example Unix: ```rexx homeDir=value('HOME', ,'ENVIRONMENT') -- maybe: "/Users/MaryDoe" ``` . slide reference="Cf. rexxref.pdf (7.4.71. VALUE)" # Temporary Directory . after steps - Every operating system defines a directory for temporary files - Rights for everyone to read and write files . after - May be emptied by the operating system, e.g. during boot process . after - Beware of storing sensitive data there! - Temporary directories on different operating systems - Windows: defined with the environment variable "`TMP`" or "`TEMP`" . after ```rexx tempDir=value('TEMP',,'ENVIRONMENT') -- maybe "C:\Users\JohnDoe\AppData\Local\Temp" ``` - MacOS: defined with the environment variable "`TMPDIR`" . after ```rexx tempDir=value('TMPDIR',,'ENVIRONMENT') -- maybe "/var/folders/x9/gyg5hmn/T/" ``` - Unix: usually the directory "`/tmp`" . slide logo=bsf4oorexx # Using Java to Fetch these Directories . after - Java's `java.util.System` class manages the properties for the system . click - The following properties are set according to the user's operating system . steps each=after level=2 | Directory | Name of System Property| |---|---| | Current directory | "`user.dir`" | | Home directory | "`user.home`" | | Temporary directory | "`java.io.tmpdir`" | . click level=2 ```rexx say "User name :" .java.lang.System~getProperty("user.name") say "User's home directory:" .java.lang.System~getProperty("user.home") say "Current directory :" .java.lang.System~getProperty("user.dir") say "Temp directory :" .java.lang.System~getProperty("java.io.tmpdir") ::requires BSF.CLS -- get ooRexx-Java bridge ``` . click level=2 Possible output (Windows) assuming current directory is C:\\Program `Files\ooRexx`: . after level=2 ```output User name : JohnDoe User's home directory: C:\Users\JohnDoe Current directory : C:\Program Files\ooRexx Temp directory : C:\Users\JohnDoe\AppData\Local\Temp\ ``` . slide card logo=none # Contact