Using cffile



You can use the cffile tag to work with files on the server in several ways:

  • Upload files from a client to the web server using an HTML form

  • Move, rename, copy, or delete files on the server

  • Read, write, or append to text files on the server

You use the action attribute to specify any of the following file actions: upload, move, rename, copy, delete, read, readBinary, write, and append. The required attributes depend on the action specified. For example, if action="write", ColdFusion expects the attributes associated with writing a text file.

Note: Consider the security and logical structure of directories on the server before allowing users access to them. You can disable the cffile tag in the ColdFusion Administrator. Also, to access files that are not located on the local ColdFusion system, ColdFusion services must run using an account with permission to access the remote files and directories.

Uploading files

File uploading requires that you create two files:

  • An HTML form to specify file upload information

  • An action page containing the file upload code

The following procedures describe how to create these files.

Create an HTML file to specify file upload information

  1. Create a ColdFusion page with the following content:

    <head><title>Specify File to Upload</title></head> 
<body> 
<h2>Specify File to Upload</h2> 
<!--- the action attribute is the name of the action page ---> 
<form action="uploadfileaction.cfm"  
        enctype="multipart/form-data"  
        method="post"> 
    <p>Enter the complete path and filename of the file to upload: 
    <input type="file" 
            name="FiletoUpload" 
            size="45"> 
    </p> 
    <input     type="submit" 
            value="Upload"> 
</form> 
</body>

  2. Save the file as uploadfileform.cfm in the myapps directory under your web_root and view it in the browser.

Note: The form does not work until you write an action page for it (see the next procedure).

Reviewing the code

The following table describes the code and its function:

Code

Description

 
<form action="uploadfileaction.cfm" enctype="multipart/form-data" method="post">

Create a form that contains file selection fields for upload by the user. The action attribute value specifies the ColdFusion template that processes the submitted form. The enctype attribute value tells the server that the form submission contains an uploaded file. The method attribute is set to post to submit a ColdFusion form.

 
<input type="file" name="FiletoUpload" size="45">

Allow the user to specify the file to upload. The file type instructs the browser to prepare to read and transmit a file from the user system to your server. It automatically includes a Browse button to let the user look for the file instead of manually entering the entire path and filename.

The user can enter a file path or browse the system and select a file to send.

  1. Create a ColdFusion page with the following content:

    <html> 
<head> <title>Upload File</title> </head> 
<body> 
<h2>Upload File</h2> 
 
<cffile action="upload" 
        destination="c:\temp\" 
        nameConflict="overwrite" 
        fileField="Form.FiletoUpload"> 
         
<cfoutput> 
You uploaded #cffile.ClientFileName#.#cffile.ClientFileExt# 
            successfully to #cffile.ServerDirectory#. 
</cfoutput> 
 
</body> 
</html>

  2. Change the following line to point to an appropriate location on your server:

    destination="c:\temp\"
    Note: This directory must exist on the server.

  3. Save the file as uploadfileaction.cfm in the myapps directory under your web_root.

  4. View uploadfileform.cfm in the browser, enter a file to upload, and submit the form.

    The file you specified uploads.

Reviewing the code

The following table describes the code and its function:

Code

Description

 
<cffile action="upload"

Output the name and location of the uploaded file on the client machine.

 
destination="c:\temp\"

Specify the destination of the file.

 
nameConflict="overwrite"

If the file exists, overwrite it.

 
fileField="Form.FiletoUpload">

Specify the name of the file to upload. Do not enclose the variable in number signs.

 
You uploaded #cffile.ClientFileName#.#cffile. 
ClientFileExt# successfully to 
#cffile.ServerDirectory#.

Inform the user of the file that was uploaded and its destination. For information on scope variables, see Evaluating the results of a file upload.
Note: This example performs no error checking and does not incorporate any security measures. Before deploying an application that performs file uploads, ensure that you incorporate both error handling and security. For more information, see Securing Applications and Handling Errors.

Resolving conflicting filenames

When you save a file to the server, a file with the same name could exist. To resolve this problem, assign one of these values to the nameConflict attribute of the cffile tag:

Error
(default) ColdFusion stops processing the page and returns an error. The file is not saved.

Skip
Allows custom behavior based on file properties. The tag does not save the file or return an error.

Overwrite
Overwrites a file that has the same name as the uploaded file.

MakeUnique
Generates a unique filename for the uploaded file. The name is stored in the file object variables serverFile and serverFileName. You can use this variable to record the name used when the file was saved. The unique name might not resemble the attempted name. For more information on file upload status variables, see Evaluating the results of a file upload.

Controlling the type of file uploaded

For some applications, you could want to restrict the type of file that is uploaded, for example, to not accept graphic files in a document library.

You use the accept attribute to restrict the type of file that you allow in an upload. When an accept qualifier is present, the uploaded file MIME content type must match the criteria specified or an error occurs. The accept attribute takes a comma-separated list of MIME data names, optionally with wildcards.

The browser determines the file MIME type. Common types, such as image/gif and text/plain, are registered in the browser.

Note: Current versions of Microsoft Internet Explorer and Netscape support MIME type associations. Other browsers and earlier versions might ignore these associations.

ColdFusion saves any uploaded file if you omit the accept attribute or specify "*/*". You can restrict the file types, as demonstrated in the following examples.

The following cffile tag saves an image file only if it is in the GIF format:

<cffile action="Upload" 
    fileField="Form.FiletoUpload" 
    destination="c:\uploads\" 
    nameConflict="Overwrite" 
    accept="image/gif">

The following cffile tag saves an image file only if it is in GIF or JPEG format:

<cffile action="Upload" 
    fileField="Form.FiletoUpload" 
    destination="c:\uploads\" 
    nameConflict="Overwrite" 
    accept="image/gif, image/jpeg">
Note: If you receive an error like "The MIME type of the uploaded file (image/jpeg) was not accepted by the server", enter accept="image/jpeg" to accept JPEG files.

This cffile tag saves any image file, regardless of the format:

<cffile action="Upload" 
    fileField="Form.FiletoUpload" 
    destination="c:\uploads\" 
    nameConflict="Overwrite" 
    accept="image/*">

Setting file and directory attributes

In Windows, you specify file attributes using attributes attribute of the cffile tag. In UNIX, you specify file or directory permissions using the mode attribute of the cffile or cfdirectory tag.

Windows

In Windows, you can set the following file attributes:

  • Hidden

  • Normal

  • ReadOnly

To specify several attributes in CFML, use a comma-separated list for the attributes attribute; for example, attributes="ReadOnly,Hidden". If you do not use the attributes attribute, the existing attributes of the file are maintained. If you specify any other attributes in addition to Normal, the additional attribute overrides the Normal setting.

UNIX

In UNIX, you can individually set permissions on files and directories for each of three types of users—owner, group, and other. You use a number for each user type. This number is the sum of the numbers for the individual permissions allowed. Values for the mode attribute correspond to octal values for the UNIX chmod command:

  • 4 = read

  • 2 = write

  • 1 = execute

You enter permissions values in the mode attribute for each type of user: owner, group, and other in that order. For example, use the following code to assign read permissions for everyone:

mode=444

To give a file or directory owner read/write/execute permissions and read-only permissions for everyone else:

mode=744

Evaluating the results of a file upload

After a file upload is completed, you can retrieve status information using file upload status variables. This status information includes data about the file, such as its name and the directory where it was saved.

You can access file upload status variables using dot notation, using either file.varname or cffile.varname. Although you can use either the File or cffile prefix for file upload status variables, cffile is preferred; for example, cffile.ClientDirectory. The File prefix is retained for backward compatibility.

Note: File status variables are read only. They are set to the results of the most recent cffile operation. If two cffile tags execute, the results of the first are overwritten by the subsequent cffile operation.

The following table describes the file upload status variables that are available after an upload:

Variable

Description

attemptedServerFile

Initial name that ColdFusion uses when attempting to save a file; for example, myfile.txt. (see Resolving conflicting filenames).

clientDirectory

Directory on the client system from which the file was uploaded.

clientFile

Full name of the source file on the client system with the filename extension; for example, myfile.txt.

clientFileExt

Extension of the source file on the client system without a period; for example, txt (not .txt).

clientFileName

Name of the source file on the client system without an extension; for example, myfile.

contentType

MIME content type of the saved file; for example, image for image/gif.

contentSubType

MIME content subtype of the saved file; for example, gif for image/gif.

dateLastAccessed

Date that the uploaded file was last accessed.

fileExisted

Indicates (Yes or No) whether the file existed with the same path.

fileSize

Size of the uploaded file.

fileWasAppended

Indicates (Yes or No) whether ColdFusion appended the uploaded file to an existing file.

fileWasOverwritten

Indicates (Yes or No) whether ColdFusion overwrote a file.

fileWasRenamed

Indicates (Yes or No) whether the uploaded file was renamed to avoid a name conflict.

fileWasSaved

Indicates (Yes or No) whether ColdFusion saved the uploaded file.

oldFileSize

Size of the file that was overwritten in the file upload operation. Empty if no file was overwritten.

serverDirectory

Directory where the file was saved on the server.

serverFile

Full name of the file saved on the server with the filename extension; for example, myfile.txt.

serverFileExt

Extension of the file saved on the server without a period; for example, txt (not .txt).

serverFileName

Name of the file saved on the server without an extension; for example, myfile.

timeCreated

Date and time the uploaded file was created.

timeLastModified

Date and time of the last modification to the uploaded file.

Moving, renaming, copying, and deleting server files

With the cffile tag, you can create application pages to manage files on your web server. You can use the tag to move files from one directory to another, rename files, copy a file, or delete a file.

The examples in the following table show static values for many of the attributes. However, the value of all or part of any attribute in a cffile tag can be a dynamic parameter.

Action

Example code

Move a file

 
<cffile action="move" source="c:\files\upload\KeyMemo.doc" destination="c:\files\memo\">

Rename a file

 
<cffile action="rename" source="c:\files\memo\KeyMemo.doc" destination="c:\files\memo\OldMemo.doc">

Copy a file

 
<cffile action="copy" source="c:\files\upload\KeyMemo.doc" destination="c:\files\backup\">

Delete a file

 
<cffile action="delete" file="c:\files\upload\oldfile.txt">

This example sets the ReadOnly flag bit for the uploaded file:

<cffile action="Copy" 
    source="c:\files\upload\keymemo.doc" 
    destination="c:\files\backup\" 
    attributes="ReadOnly">
Note: Ensure that you include the trailing slash (\) when you specify the destination directory. Otherwise, ColdFusion treats the last element in the path as a filename. This rule only applies to copy actions.

Reading, writing, and appending to a text file

In addition to managing files on the server, you can use the cffile tag to read, create, and modify text files. As a result, you can do the following things:

  • Create log files. (You can also use cflog to create and write to log files.)

  • Generate static HTML documents.

  • Use text files to store information that can be incorporated into web pages.

Reading a text file

You can use the cffile tag to read an existing text file. The file is read into a local variable that you can use anywhere in the application page. For example, you could read a text file and then insert its contents into a database, or you could read a text file and then use one of the string replacement functions to modify the contents.

Read a text file

  1. Create a ColdFusion page with the following content:

    <html> 
<head> 
    <title>Read a Text File</title> 
</head> 
 
<body> 
Ready to read the file:<br> 
<cffile action="read" 
    file="C:\inetpub\wwwroot\mine\message.txt" 
    variable="Message"> 
 
<cfoutput> 
    #Message# 
</cfoutput> 
</body> 
</html>

  2. Replace C:\inetpub\wwwroot\mine\message.txt with the location and name of a text file on the server.

  3. Save the file as readtext.cfm in the myapps directory under your web_root and view it in the browser.

Writing a text file on the server

You can use the cffile tag to write a text file based on dynamic content. For example, you could create static HTML files or log actions in a text file.

Create a form in to capture data for a text file

  1. Create a ColdFusion page with the following content:

    <html> 
<head> 
    <title>Put Information into a Text File</title> 
</head> 
 
<body> 
<h2>Put Information into a Text File</h2> 
 
<form action="writetextfileaction.cfm" method="Post"> 
    <p>Enter your name: <input type="text" name="Name" size="25"></p> 
    <p>Enter the name of the file: <input type="text" name="FileName" size="25">.txt</p> 
    <p>Enter your message: 
    <textarea name="message"cols=45 rows=6></textarea> 
    </p> 
    <input type="submit" name="submit" value="Submit">  
</form> 
</body> 
</html>

  2. Save the file as writetextfileform.cfm in the myapps directory under your web_root.

Note: The form does not work until you write an action page for it (see the next procedure).

Write a text file

  1. Create a ColdFusion page with the following content:

    <html> 
<head> 
    <title>Write a Text File</title> 
</head> 
<body> 
<cffile action="write" 
    file="C:\inetpub\wwwroot\mine\#Form.FileName#.txt" 
    output="Created By: #Form.Name# 
#Form.Message# "> 
</body> 
</html>

  2. Modify the path C:\inetpub\wwwroot\mine\ to point to a path on your server.

  3. Save the file as writetextfileaction.cfm in the myapps directory under your web_root.

  4. View the file writetextfileform.cfm in the browser, enter values, and submit the form.

    The text file is written to the location you specified. If the file exists, it is replaced.

Appending a text file

You can use the cffile tag to append additional text to the end of a text file; for example, when you create log files.

Append a text file

  1. Open the writetextfileaction.cfm file.

  2. Change the value for the action attribute from write to append so that the file appears as follows:

    <html> 
<head> 
    <title>Append a Text File</title> 
</head> 
<body> 
<cffile action="append" 
    file="C:\inetpub\wwwroot\mine\message.txt" 
    output="Appended By: #Form.Name#"> 
</body> 
</html>

  3. Save the file as writetextfileaction.cfm in the myapps directory under your web_root.

  4. View the file in the browser, enter values, and submit the form.

    The appended information displays at the end of the text file.