Useful Unix commands

gistfile1.txt

    dig, host - fetches DNS information
    fuser - displays the PIDs of processes using the specified files or file systems.
    gcore - generate a core file of a running program
    gdb - allow you to see what is going on ''inside'' another program / coredump
    iotop - watches I/O usage information output and displays a table of current I/O usage by processes or threads on the system
    lftp - a file transfer program that allows sophisticated ftp, http and other connections to other hosts (including parallel transfer)
    lsof - lists on its standard output file information about files opened by processes
    nc - networking utility for reading from and writing to network connections using TCP or UDP
    nmon - a huge amount of important performance information in one go
    pbzip2 - a parallel implementation of the bzip2 block-sorting file compressor that uses pthreads and achieves near-linear speedup on SMP machines
    pmap - reports the memory map of a process or processes
    pstack - print a stack trace of a running process
    pstree - print hierarchy of processes
    sar - writes to standard output the contents of selected cumulative activity counters in the operating system
    strace - trace system calls and signals
    wget - free utility for non-interactive download of files from HTTP/HTTPS/FTP servers