Thanks a lot. I got it.
On Tue, May 21, 2013 at 6:42 AM, Cameron Simpson <c...@zip.com.au> wrote: > On 20May2013 15:05, Avnesh Shakya <avnesh.n...@gmail.com> wrote: > | Thanks a lot. > > No worries, but ... > > AGAIN: > - please DO NOT top post. Post below, trimming the quoted material. > - please POST TO THE LIST, not just to me. This is a public discussion. > > Now... > > | I did something. > | I have created test.sh file in which i put- > | > | #!/bin/bash > | cd /home/avin/cronJob > | python try.py > > Ok, good. Some minor remarks: > > Personally, I always use: > > #!/bin/sh > > instead of requiring bash. All UNIX systems have sh, bash is only > common. And even when present, it may not be in /bin. /bin/sh is > always there, and unless you're doing something quite unusual, it > works just fine. > > | then i went on terminal - > | and run crontab -e > | and wrote- > | */2 * * * * bash /home/avin/cronJob/test.sh > | and saved it. > > IIRC, this runs every two minutes. Good for testing, but not your original > spec. > > Also, if you make the shell script (test.sh) executable you do not > need to specify the interpreter. Treat your script like any other > command! So: > > chmod +rx /home/avin/cronJob/test.sh > > and then your cron line can look like this: > > */2 * * * * /home/avin/cronJob/test.sh > > Also, treat your script the same way as your shell script, start > it with a #! like this: > > #!/usr/bin/python > > Make it executable: > > chmod +rx /home/avin/cronJob/try.py > > and then you don't need to say "python" in your shell script: > > ./try.py > > (You need the ./ because the current directory is not in your command > search path ($PATH).) > > | It's working fine. > | but when I m using like > | > | import random > | a = random.randrange(0, 59) > | */a * * * * bash /home/avin/cronJob/test.sh > | then it's showing error becose of varable 'a', so now how can i take > | variable? > > I take it that this is your python program intended to schedule the two > randomly timed runs? > > As a start, it must all be python. The first two lines are. The third line > is > a crontab line. > > So as a start, you need to look more like this: > > #!/usr/bin/python > import random > a = random.randrange(0, 59) > cronline = '*/%d * * * * /home/avin/cronJob/test.sh' % (a,) > print(cronline) > > At least then you can see the cron line you're making. It still > does not add it to a cron job. > > Some remarks: > > - randrange() is like other python ranges: it does not include the end > value. > So your call picks a number from 0..58, not 0..59. > Say randrange(0,60). Think "start, length". > > - My recollection is that you wanted to run a script twice a day at random > times. > Your cron line doesn't do that. > > - If you're picking random run times you want to schedule a once-off > job for each to run at a particular times. Cron schedules repeating > jobs. To run at a particular time you want an "at" job. > > - You need to do one of two things in the pick-a-time script: > - pick a time, then sleep until that time and then directly > invoke the try.py script > or > - pick a time, then use the "at" command to schedule the try.py > (or test.sh) script. > > The first approach would look a bit like this (totally untested): > > #!/usr/bin/python > import random > import subporcess > import time > # choose range time in the next 24 hours > when = random.randrange(0, 24 * 3600) > # sleep that many seconds > time.sleep(when) > subprocess.call(['/home/avin/cronJob/test.sh']) > > For two runs, pick two times. Swap them into order. Sleep twice, > once until the first time and then once until the second time. Etc. > > The second approach (using "at") would not sleep. instead, compute > (using the datetime module) the date and time each job should run, > and invoke "at" using the subprocess module, piping the text > "/home/avin/cronJob/test.sh\n" to it. > > Cheers, > -- > Cameron Simpson <c...@zip.com.au> > > On a related topic, has anyone looked at doing a clean-room copy of CSS > a la RC2 and RC4 a few years back? I know one or two people have > looked at this in an informal manner, but we couldn't find anyone who > hadn't already seen the DeCSS code to act as the clean person (it says > a lot for the status of their "trade secret" that we couldn't actually > find anyone who didn't already know it). > - Peter Gutmann <pgut...@cs.auckland.ac.nz> >
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