#include <sys/time.h> #include <sys/resource.h>
int getrlimit(resource, rlp) int resource; struct rlimit *rlp;
int setrlimit(resource, rlp) int resource; struct rlimit *rlp;
Limits on the consumption of system resources by the current process and each process it creates may be obtained with the getrlimit() call, and set with the setrlimit() call.
The resource parameter is one of the following:
A resource limit is specified as a soft limit and a hard limit. When a soft limit is exceeded a process may receive a signal (for example, if the cpu time is exceeded), but it will be allowed to continue execution until it reaches the hard limit (or modifies its resource limit). The rlimit structure is used to specify the hard and soft limits on a resource,
struct rlimit { int rlim_cur; /* current (soft) limit */ int rlim_max; /* hard limit */ };
Only the super-user may raise the maximum limits. Other users may only alter rlim_cur within the range from 0 to rlim_max or (irreversibly) lower rlim_max.
An ``infinite'' value for a limit is defined as RLIM_INFINITY (0x7fffffff).
Because this information is stored in the per-process information,
this system call must be executed directly by the shell if it
is to affect all future processes created by the shell;
limit
is thus a built-in command to
csh.1
The system refuses to extend the data or stack space when the limits would be exceeded in the normal way: a brk() or sbrk() call will fail if the data space limit is reached, or the process will be sent a SIGSEGV when the stack limit is reached which will kill the process unless SIGSEGV is handled on a separate signal stack (since the stack cannot be extended, there is no way to send a signal!).
A file I/O operation that would create a file that is too large generates a signal SIGXFSZ; this normally terminates the process, but may be caught. When the soft CPU time limit is exceeded, a signal SIGXCPU is sent to the offending process.
In addition to the above, setrlimit() may set errno to:
There should be limit and unlimit commands in sh.1 as well as in csh.1
Created by unroff & hp-tools. © somebody (See intro for details). All Rights Reserved. Last modified 11/5/97