Implemented Steps

File System

findFiles - Find/list files in the workspace. Returns an array of FileWrappers (help)
prependToFile - Create a file (if not already exist) in the workspace, and prepends given content to it. Returns a FileWrapper representing the file that was prepended. (help)
touch - Create a file (if not already exist) in the workspace, and set the timestamp. Returns a FileWrapper representing the file that was touched. (help)
sha1 - Computes the SHA1 of a given file. (help)
sha256 - Computes the SHA-256 of a given file. (help)
verifySha1 - Verifies the SHA-1 of a given file. (help)
verifySha256 - Verifies the SHA-256 of a given file. (help)
tee - Tee output to file

Tar/tar.gz/tgz Files

tar - Create Tar file. (help)
untar - Extract Tar file (help)

Zip Files

zip - Create Zip file. (help)
unzip - Extract/Read Zip file (help)

Configuration Files

readProperties - Read java properties from files in the workspace or text. (help)
readManifest - Read a Jar Manifest. (help)
readYaml - Read YAML from files in the workspace or text. (help)
writeYaml - Write YAML to a file or String from an object or collection of objects. (help)
readJSON - Read JSON from files in the workspace or text. (help)
writeJSON - Write a JSON object to a file in the workspace, or to a String. (help)
readCSV - Read CSV from files in the workspace or text. (help)
writeCSV - Write a CSV file from an object. (help)

Maven Projects

readMavenPom - Read a Maven Project into a Model data structure. (help)
writeMavenPom - Write a Model data structure to a file. (help)

Jenkins

nodesByLabel - List nodes by Label, by default excluding offline. Returns a list of node names as List<String>. (help)

Misc

compareVersions - Compare two version numbers with each other. (help)