The ulimit Command The ulimit command manipulates system resource limits for current and child processes using the following format: ulimit [options] or ulimit [options] n where n indicates to set a resource limit to n (except with the a option). If n is not given, the specified resource limit is displayed. If no option is given, the default f (file size limit) is used. Here, all the current resource limits are displayed: $ ulimit a time(seconds) unlimited memory(kbytes) unlimited data(kbytes) 4294901761 stack(kbytes) 2048 file(blocks) unlimited coredump(blocks) unlimited This command sets the core dump size limit to 500 blocks: $ ulimit c 500 To disable generation of core dumps, the dump size should be set to 0 blocks: $ ulimit c 0 To display the current file size write limit, use ulimit without arguments: $ ulimit unlimited Table 9.1 lists the ulimit options. If a size argument is not given, the current limit is displayed. Table 9.1. ulimit Options| a | displays all the current resource limits | | c n | set the core dump size limit to n 512-byte blocks | | d n | set the data area size limit to n kilobytes | | f n | set the child process file write limit to n 512-byte blocks (default) | | m n | set the physical memory size limit to n kilobytes | | s n | set the stack area size limit to n kilobytes | | t n | set the process time limit to n seconds |
The ulimit command is system dependent. Some systems may have different resource limits, and some may not allow changing resource limits. Check your local system documentation for discrepancies. | 
