libqexec - Lib Quick Exec for Java

A faster Runtime.exec for Java

How does it work?

Native libraries of course. It simply calls popen() for you in a C library.

How much faster? (All results in ms)

A lot faster. Look at these results;

• Table: Note: all the results are is ms

• Graph of echo hello

• Graph of md5sum test
• Note: test is a 20 mb file, and the same one was used across all tests

• Graph of dd if=/dev/urandom of=test count=20 bs=1M
• Note: I was doing this on a slower ARM system so the results may be faster for you

How to use it.

Simple. Download or compile the library under the native/. Then integrate the Java source with yours. On your java app startup, add the flag -Djava.library.path="/path/to/library so the program can find the native library.

Static methods in QExec:

public static String exec(String cmd, int bufSize) Executes the command as specified:

• String cmd. This is a string containing the command you would like to execute
• int bufSize. This is the buffer size for when building the output string in the C lib. Just use QExec.DEFAULT_BUFFER_SIZE.
• Returns the String containing the output of the command.

public static void execToConsole(String cmd) Executes the command and outputs the output of the command to the System.out

• String cmd. A string containing the command you would like to execute

public static void execToNull(String cmd) Does the same as execToConsole except it appends > /dev/null/> NUL, therefore not outputting to the console. Don't use this if the command contains | or >.