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Annotation of cci/usr/src/man/man3/vlimit.3c, revision 1.1.1.1

1.1       root        1: .TH VLIMIT 3C "18 July 1983"
                      2: .UC 4
                      3: .SH NAME
                      4: vlimit \- control maximum system resource consumption
                      5: .SH SYNOPSIS
                      6: .B "#include <sys/vlimit.h>"
                      7: .PP
                      8: .B vlimit(resource, value)
                      9: .SH DESCRIPTION
                     10: .ft B
                     11: This facility is superseded by getrlimit(2).
                     12: .ft R
                     13: .PP
                     14: Limits the consumption by the current process and each process
                     15: it creates to not individually exceed 
                     16: .I value
                     17: on the specified
                     18: .I resource.
                     19: If
                     20: .I value
                     21: is specified as \-1, then the current limit is returned and the
                     22: limit is unchanged.
                     23: The resources which are currently controllable are:
                     24: .TP 15
                     25: LIM_NORAISE
                     26: A pseudo-limit; if set non-zero then the limits may not be raised.
                     27: Only the super-user may remove the \fInoraise\fR restriction.
                     28: .TP 15
                     29: LIM_CPU
                     30: the maximum
                     31: number of cpu-seconds to be used by each process
                     32: .TP 15
                     33: LIM_FSIZE
                     34: the largest single file which can be created
                     35: .TP 15
                     36: LIM_DATA
                     37: the maximum growth of the data+stack region via
                     38: .IR sbrk (2)
                     39: beyond the end of the program text
                     40: .TP 15
                     41: LIM_STACK
                     42: the maximum
                     43: size of the automatically-extended stack region
                     44: .TP 15
                     45: LIM_CORE
                     46: the size of the largest core dump that will be created.
                     47: .TP 15
                     48: LIM_MAXRSS
                     49: a soft limit for the amount of physical memory (in bytes) to be given
                     50: to the program.  If memory is tight, the system will prefer to take memory
                     51: from processes which are exceeding their declared LIM_MAXRSS.
                     52: .PP
                     53: Because this information is stored in the per-process information
                     54: this system call must be executed directly by the shell if it
                     55: is to affect all future processes created by the shell;
                     56: .I limit
                     57: is thus a built-in command to
                     58: .IR csh (1).
                     59: .PP
                     60: The system refuses to extend the data or stack space when the limits
                     61: would be exceeded in the normal way; a
                     62: .I break
                     63: call fails if the data space limit is reached, or the process is
                     64: killed when the stack limit is reached (since the stack cannot be
                     65: extended, there is no way to send a signal!).
                     66: .PP
                     67: A file i/o operation which would create a file which is too large
                     68: will cause a signal SIGXFSZ to be generated, this normally terminates
                     69: the process, but may be caught.
                     70: When the cpu time limit is exceeded, a signal SIGXCPU is sent to the
                     71: offending process; to allow it time to process the signal it is
                     72: given 5 seconds grace by raising the cpu time limit.
                     73: .SH SEE ALSO
                     74: csh(1)
                     75: .SH BUGS
                     76: If LIM_NORAISE is set, then no grace should be given when the cpu
                     77: time limit is exceeded.
                     78: .PP
                     79: There should be 
                     80: .I limit
                     81: and
                     82: .I unlimit
                     83: commands in
                     84: .IR sh (1)
                     85: as well as in
                     86: .IR csh.
                     87: .PP
                     88: This call is peculiar to this version of UNIX.
                     89: The options and specifications of this system call and even the call itself
                     90: are subject to change.  It may be extended or replaced by other
                     91: facilities in future versions of the system.

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