174 reputation
8
bio website jeremykun.com
location Chicago
age
visits member for 2 years, 6 months
seen Mar 17 at 18:06

PhD Candidate at UI Chicago.


Dec
27
comment Please explain the output from the jobs command
Always wondered what the +/- mean.
Jul
16
awarded  Popular Question
Nov
1
comment Running two animations side-by-side using ImageMagick
the montage command is what did it eventually, but I resolved this on my own months ago...
Nov
1
accepted Running two animations side-by-side using ImageMagick
Jun
6
awarded  Critic
Jun
6
comment Running two animations side-by-side using ImageMagick
This does not do what I want. Instead, it concatenates the animations. I want it to run the two simultaneously side by side.
Jun
6
asked Running two animations side-by-side using ImageMagick
May
30
awarded  Commentator
May
30
accepted Collapsing a stream of multiple lines into one line
May
30
comment Collapsing a stream of multiple lines into one line
I knew it could be done with sed, but you're right, tr is better. Yet another two-letter unix utility to add to my belt.
May
25
asked Collapsing a stream of multiple lines into one line
Jan
20
awarded  Supporter
Jan
20
comment Permissions for a submission script
Point taken. In any event, I don't have permissions to download or install anything on the server we're using (shared with some other classes, apparently), and I certainly didn't set up their home directories. So homegrown it is.
Jan
19
awarded  Teacher
Jan
19
comment Permissions for a submission script
To untaint a variable containing user data, one must match it against a regular expression (the if statement, the most complex part of the program), and then extract the captured part of the matched expression (here, the variable $1). In other words, this will ensure your user entered data in the way you expected him to.
Jan
19
comment Permissions for a submission script
@FaheemMitha In perl, one considers all data that originates from the user to be unclean, or "tainted". In particular, if a user supplies a devious enough command line argument (which I then pass to copy or chmod), then they can potentially take over the running process and gain my privileges indefinitely. If you run a perl with the setuid bit enabled, it enforces some additional constraints, including that all user data must be untainted before it could be used in a potentially harmful way. (ctd...)
Jan
19
comment Permissions for a submission script
For some reason I set it nonreadable and they couldn't run it... But with luck the script is bullet-proof enough that they can read it and not take advantage of it anyway. Also, they are intro programmers, so they certainly don't know Perl.
Jan
18
awarded  Editor
Jan
18
revised Permissions for a submission script
added script
Jan
18
comment Permissions for a submission script
At the risk of exposing my novice perl skills? sure why not.