grepjar

grepjar [options] pattern jarfile...

-i
    Ignore case distinctions, so that characters that differ only in case match each other.

-r
    Recursively search subdirectories for JAR files.

-l
    List only the names of files containing matching lines, instead of the matching lines themselves.

-v
    Select non-matching lines.

-h
    Suppress the prefixing of file names on output.

-n
    Prefix each line of output with the line number within its input file.

grepjar is a command-line tool used to search for patterns within JAR (Java Archive) files. It essentially combines the functionality of grep and the ability to access the contents of JAR files without manually extracting them. This allows developers to quickly find specific strings, class names, or other text-based content within the JAR archives, which are essentially ZIP files containing Java classes, resources, and metadata. This is very helpful to locate dependencies within the archives.

Instead of manually unzipping each JAR file and then using grep, grepjar automates this process, making it significantly faster and more efficient. It can recursively search through multiple JAR files, and even nested JAR files within archives. The usage of this command is convenient and reduces time spent with extracting and searching.

grepjar might not handle all JAR file formats flawlessly, especially if they are corrupted or use uncommon compression methods.

Binary files within JAR archives are treated as text, which may lead to gibberish output. Performance can degrade with a very large number of JAR files or extremely large archives. It is important to specify the files to search, instead of searching every jar file. Performance is optimized if it is clear where to search for.

The grepjar command exits with a status of 0 if matches are found, 1 if no matches are found, and 2 if errors occurred.

• To search for 'MyClass' in all JAR files in the current directory:
  grepjar MyClass *.jar
• To recursively search for 'MyClass' in all JAR files within a directory:
  grepjar -r MyClass /path/to/directory
• To list only the names of JAR files containing 'MyClass':
  grepjar -l MyClass *.jar

grepjar's development evolved from the need to efficiently search within JAR files, a common task in Java development. It was created to streamline the process of finding specific code or resources within Java archives, which traditionally involved manually extracting the JAR files and then using grep. This command became popular for its convenience and time-saving capabilities in the Java ecosystem.

grep(1), jar(1), zip(1), find(1)