The “ulimit” and “limit” commands are often built into the shell, but there may exist some binaries with the same name. For example:
# /usr/local/bin/bash
bash> type ulimit
ulimit is a shell builtin
bash> which ulimit
/usr/bin/ulimit
The command can also alter with the different shells:
# /bin/sh
sh> type ulimit
ulimit is a shell builtin
# /bin/csh
% which limit
builtin/limit
When one of these is a shell built-in, you may not get much useful from running some external program with the same (or a similar) name. Also, the syntax may be different for each of these. In a C shell, I’d suggest using “limit”:
% limit
cputime unlimited
filesize unlimited
datasize 1048576 kbytes
stacksize 8192 kbytes
coredumpsize unlimited
memoryuse 2024568 kbytes
descriptors 4096 files
addressspace 4194304 kbytes
% limit coredumpsize 1000000
% limit
cputime unlimited
filesize unlimited
datasize 1048576 kbytes
stacksize 8192 kbytes
coredumpsize 1000000 kbytes
memoryuse 2024568 kbytes
descriptors 4096 files
addressspace 4194304 kbytes
To learn more about these shell built-ins you can do “man bash”, “man csh”, “man sh”, or “man