179 reputation
19
bio website jeremykun.com
location Chicago
age
visits member for 2 years, 10 months
seen Aug 26 at 0:36

PhD Candidate at UI Chicago.


Sep
24
awarded  Autobiographer
Sep
9
awarded  Notable Question
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