Commands by l0b0 (7)

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Resume scp of a big file

Extract audio from start to end position from a video
mplayer -vc null -vo null -ao pcm Firefly\ ep\ 10.avi -ss 195 -endpos 246 Will create file audiodump.wav with audio from second 195 to second 246 (the opnening theme).

Show what PID is listening on port 80 on Linux

check open ports without netstat or lsof

Grabs a random image from "~/wallpapers" and sets as the background
don't bother spawning a bc process or counting the number of options, just pick a random one. 'sort -R' sorts randomly, so pick the top one.

Get Dollar-Euro exchage rate
You can get others rates changing the "EUR/US" part. look at the url: wap.kitco.com/exrate.wml to get more options.

Determine if a command is in your $PATH using POSIX
it is generally advised to avoid using which(1) whenever possible. which(1) is usually a csh(1) script, or sometimes a compiled binary. It's output is highly variable from operating system to operating system, so platform independent scripts could become quite complicated with the logic. On HP-UX 10.20, for example, it prints "no bash in /path /path /path ..."; on OpenBSD 4.1, it prints "bash: Command not found."; on Debian (3.1 through 5.0 at least) and SuSE, it prints nothing at all; on Red Hat 5.2, it prints "which: no bash in (/path:/path:...)"; on Red Hat 6.2, it writes the same message, but on standard error instead of standard output; and on Gentoo, it writes something on stderr. And given all these differences, it's still variable based on your shell. This is why POSIX is king. See http://mywiki.wooledge.org/BashFAQ/081 for more ways on avoiding which(1).

Use /dev/full to test language I/O-failsafety
The Linux /dev/full file simulates a "disk full" condition, and can be used to verify how a program handles this situation. In particular, several programming language implementations do not print error diagnostics (nor exit with error status) when I/O errors like this occur, unless the programmer has taken additional steps. That is, simple code in these languages does not fail safely. In addition to Perl, C, C++, Tcl, and Lua (for some functions) also appear not to fail safely.

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

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"


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