First is that many people have their computers to either sleep or hibernate after a certain amount of time. There are a couple drawbacks to this, of course. It’s simple! The ‘sleep’ command will wait 8 hours, then when the time is up, will quit, allowing the second command – where the music is actually played – to begin. Our final command? Assuming we want to sleep for 8 hours: We’ll combine the two commands with ‘&’ which will run the first command, then only after it completes run the second. The solution? Use the ‘sleep’ command and our music player together. Of course, the drawback (when trying to create our alarm clock), is that the song plays immediately. Typing this into the Terminal (replacing the actual path and name of the music file, of course), we would be able to listen to whatever song we want. To invoke mplayer, for instance, we would use this command: For our music player, we’ll use mplayer, but you could just as easily use Totem, VLC, Banshee, or whatever your favorite music player is. To make this a true alarm clock, we’ll need to add to the command. It’s easy! Of course, once your time has elapsed, nothing else will happen, because all the ‘sleep’ command does is count down your sleep amount. You can even combine commands, so if you wanted to sleep for 5 hours and 30 minutes, you would use a single ‘sleep’ command with both times: Join the nixCraft community via RSS Feed, Email Newsletter or follow on Twitter.Finally, to sleep for 10 days, use this command: He wrote more than 7k+ posts and helped numerous readers to master IT topics. Vivek Gite is the founder of nixCraft, the oldest running blog about Linux and open source. Apart from C code one can use Perl or shell too. You learned how to run Linux or Unix commands under an alarm clock to set Timeout, either setitimer(2) or RLIMIT_CPU. This page explains how to start a command, and kill it if the specified timeout expires: path/to/foo bar & sleep 5 kill $! say hello to timeout command Set sleep time with the command, & condition sa follows: How to timeout a command in Linux or Unix shell For the limit timer, zero raises command’s cpu limit to the hard maximum (typically unlimited). For interval timers, a secs value of zero clears an inherited alarm, if any. Interval timers may alarm just once, or may recurrently alarm (-r), signalling every secs seconds. See OPTIONS below for timers and respective signals. Available process timers come in two types: interval and limit. The default timer expires with a (normally fatal) SIGALRM after secs real seconds. The doalarm executes command fooo under an impending alarm. r -recur Recurring alarm, every sec seconds. timer= 'profile' (SIGPROF), 'cpu' (SIGXCPU). t Type of timer: 'real' (SIGALRM), 'virtual' (SIGVTALRM), Sample output: Error: missing required parameter (Credit: Heiner Steven) doalarm c programĭownload doalarm program using the wget command or curl command & Fatal "please do not use -p option interactively" #echo >&2 "DEBUG: $$: parent PID to terminate is $ParentPID" exec >/dev /null 0 & 1 # Suppress error messages sleep $Timeout kill $ParentPID & # Give process time to terminate ( sleep 2 kill -1 $ParentPID ) & ( sleep 2 kill -9 $ParentPID ) exit 0 fi & Fatal "please specify a command to execute" "$0" -p $$ -t $Timeout & # Start watchdog #echo >&2 "DEBUG: process id is $$" exec # Run command exit 2 # NOT REACHED else # We run in "watchdog" mode, $ParentPID contains the PID # of the process we should terminate after $Timeout seconds. # Start "watchdog" process, and then run the command. Usage ( ) # Set default if then # This is the first invokation of this script. # PN= ` basename "$0" ` # Program name VER= '1.3' TIMEOUT= 5 # Default timeout command.") it will # terminate the login session. # o If this script runs in the environment of the login shell # (i.e. # o The "watchdog" process is invoked by the name "$0", so # "$0" must be a valid path to the script. # Notes # o Uses the internal command line argument "-p" to specify the # PID of the process to terminate after the timeout to the # "watchdog" process. # If the command did not terminate after the specified # number of seconds, the "watchdog" process will terminate # the command by sending a signal. timeoutđ.3 03/03/18 # Description # o Runs a command, and terminates it (by sending a signal) after # a specified time period # o This command first starts itself as a "watchdog" process in the # background, and then runs the specified command. # Shellscript: timeout - set timeout for a command # Alarm clock Set Timeout # Author : Heiner Steven # Date : # Category :ğile Utilities # Requires : # SCCS-Id.
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