Commands tagged gstreamer (3)

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List commands with a short summary
Obviously, you can replace 'man' command with any command in this command line to do useful things. I just want to mention that there is a way to list all the commands which you can execute directly without giving fullpath. Normally all important commands will be placed in your PATH directories. This commandline uses that variable to get commands. Works in Ubuntu, will work in all 'manpage' configured *nix systems.

Explanation of system and MySQL error codes
perror should be installed if mysql-server package is installed

Crash bash, in case you ever want to for whatever reason
This is a very hackish way to do it that I'm mainly just posting for fun, and I guess technically can more accurately be said to result in undefined behavior. What the command does is tell the shell to treat libpng like it's a shell plugin (which it's most certainly not) and attempt to install a "png_create_read" command from the library. It looks for the struct with the information about the command; since it's always the command name followed by "_struct", it'll look for a symbol called "png_create_read_struct". And it finds it, since this is the name of one of libpng's functions. But bash has no way to tell it's a function instead of a struct, so it goes ahead and parses the function's code as if it was command metadata. Inevitably, bash will attempt to dereference an invalid pointer or whatever, resulting in a segfault.

Bypass with hexencoding, dump /etc/passwd

split and combine different pages from different pdf's
The command shows the real power of the pdftk tool, you can do basically everything you want with multiple pdf's. In the command a book is created from chapters, headings and covers.

recursive reset file/dir perms
Good for fixing web permissions. You might also want to do something like this and skip files or directories that begin with a period: $ find public_html/stuff -not -name ".*" \( -type d -exec chmod 755 {} + -o -type f -exec chmod 644 {} + \) ...or include a special case for scripts: $ find public_html/stuff -type d -exec chmod 755 {} + -or -type f -name "*.pl" -exec chmod 755 {} + -or -exec chmod 644 {} +

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

unbuffered tcpdump
Sometimes the question comes up: How to get unbuffered tcpdump output into the next program in the pipe? i.e. if your OS forces you to wait for the buffer to fill before the next program sees any of the output If you use -Uw- then you can't use -A (or -X or -XX) at the same time. When the question comes up, I've never seen anyone suggest this simple solution: chaining 2 tcpdump instances.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

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