File Functions

Use file functions to return information about a file name or path. For example, you might use a file function to remove a file extension from a file path or to return part of the path.

You can replace any argument with a literal or an expression that evaluates to the argument. String literals must be enclosed in single or double quotation marks.

Not valid in Data Collector Edge pipelines. Do not use file functions in Data Collector Edge pipelines.

The expression language provides the following file functions:
file:fileExtension(<filepath>)
Returns the file extension from a file path. Uses the following argument:
  • filepath - An absolute path to a file.
Return type: String.
For example, the following expression returns "txt": 
${file:fileExtension('/logs/weblog.txt')}
file:fileName(<filepath>)
Returns the file name from a file path. Uses the following argument:
  • filepath - An absolute path to a file.
Return type: String.
For example, the following expression returns the filename, "weblog.txt":
${file:fileName('/logs/weblog.txt')}
file:parentPath(<filepath>)
When used with a path to a file, returns the path to the file without the final separator, such as /files for /files/file.log.
When used with a path to a directory, returns the path to the directory without the final separator, such as /serverA/logs for /serverA/logs/2016.
Uses the following argument:
  • filepath - An absolute path to a file.
Return type: String.
For example, the following expression, which includes a path to a file, returns "/serverB/logs":
${file:parentPath('/serverB/logs/weblog.txt')}
Similarly, the following expression, which includes a path to a directory, returns the parent directory, "/serverB/logs":
${file:parentPath('/serverB/logs/weblogs')}
file:pathElement(<filepath>, <integer>)
Returns the part of a path based on the specified integer. Uses the following arguments:
  • filepath - An absolute path to a file.
  • integer - The section of a path to return. Can return parts starting from the left or right side of the path:
    • To return a section of a path, counting from the left side of the path, use 0 and positive integers and start with 0.
    • To return a section of a path, counting from the right side of the path, use negative integers and start with -1.
Return type: String.
For example, to return the logs portion of the path, you can use either of the following expressions:
${file:pathElement('/logs/weblog.txt',0)}
${file:pathElement('/logs/weblog.txt',-2)}
file:removeExtension(<filepath>)
Returns the file path without the file extension. Uses the following argument:
  • filepath - An absolute path to a file.
Return type: String.
For example, the following expression returns "/logs/weblog":
${file:removeExtension('/logs/weblog.txt')}