163773Sbostic.\" Copyright (c) 1993 263773Sbostic.\" The Regents of the University of California. All rights reserved. 360275Sbostic.\" 460275Sbostic.\" %sccs.include.redist.roff% 560275Sbostic.\" 6*66958Sbostic.\" @(#)sysconf.3 8.3 (Berkeley) 04/19/94 760275Sbostic.\" 860275Sbostic.Dd 960275Sbostic.Dt SYSCONF 3 1060275Sbostic.Os BSD 4 1160275Sbostic.Sh NAME 1260275Sbostic.Nm sysconf 1360275Sbostic.Nd get configurable system variables 1460275Sbostic.Sh SYNOPSIS 1560275Sbostic.Fd #include <unistd.h> 1660275Sbostic.Ft long 1760275Sbostic.Fn sysconf "int name" 1860275Sbostic.Sh DESCRIPTION 1960275Sbostic.Pp 2063772SmckusickThis interface is defined by 2163772Smckusick.St -p1003.1-88 . 2263772SmckusickA far more complete interface is available using 2363772Smckusick.Xr sysctl 3 . 2463772Smckusick.Pp 2560275SbosticThe 2660275Sbostic.Fn sysconf 2760275Sbosticfunction provides a method for applications to determine the current 2860275Sbosticvalue of a configurable system limit or option variable. 2960275SbosticThe 3060275Sbostic.Fa name 3160275Sbosticargument specifies the system variable to be queried. 3260275SbosticSymbolic constants for each name value are found in the include file 3360275Sbostic.Li <unistd.h> . 3460275Sbostic.Pp 3560275SbosticThe available values are as follows: 3660275Sbostic.Pp 3760275Sbostic.Bl -tag -width "123456" 3860275Sbostic.Pp 3960275Sbostic.It Li _SC_ARG_MAX 4060275SbosticThe maximum bytes of argument to 4160275Sbostic.Xr exec 2 . 4260275Sbostic.It Li _SC_CHILD_MAX 4360275SbosticThe maximum number of simultaneous processes per user id. 4460275Sbostic.It Li _SC_CLK_TCK 4560275SbosticNumber of micro-seconds per hz tick. 4660275Sbostic.It Li _SC_NGROUPS_MAX 4760275SbosticThe maximum number of supplemental groups. 4860275Sbostic.It Li _SC_OPEN_MAX 4960275SbosticThe maximum number of open files per user id. 5060275Sbostic.It Li _SC_STREAM_MAX 5160275SbosticThe minimum maximum number of streams that a process may have open 5260275Sbosticat any one time. 5360275Sbostic.It Li _SC_TZNAME_MAX 5460275SbosticThe minimum maximum number of types supported for the name of a 5560275Sbostictimezone. 5660275Sbostic.It Li _SC_JOB_CONTROL 5760275SbosticReturn 1 if job control is available on this system, otherwise \-1. 5860275Sbostic.It Li _SC_SAVED_IDS 5960275SbosticReturns 1 if saved set-group and saved set-user ID is available, 6060275Sbosticotherwise \-1. 6160275Sbostic.It Li _SC_VERSION 6260275SbosticThe version of ISO/IEC 9945 (POSIX 1003.1) with which the system 6360275Sbosticattempts to comply. 6460275Sbostic.It Li _SC_BC_BASE_MAX 6560275SbosticThe maximum ibase/obase values in the 6660275Sbostic.Xr bc 1 6760275Sbosticutility. 6860275Sbostic.It Li _SC_BC_DIM_MAX 6960275SbosticThe maximum array size in the 7060275Sbostic.Xr bc 1 7160275Sbosticutility. 7260275Sbostic.It Li _SC_BC_SCALE_MAX 7360275SbosticThe maximum scale value in the 7460275Sbostic.Xr bc 1 7560275Sbosticutility. 7660275Sbostic.It Li _SC_BC_STRING_MAX 7760275SbosticThe maximum string length in the 7860275Sbostic.Xr bc 1 7960275Sbosticutility. 8060275Sbostic.It Li _SC_COLL_WEIGHTS_MAX 8160275SbosticThe maximum number of weights that can be assigned to any entry of 8260275Sbosticthe LC_COLLATE order keyword in the locale definition file. 8360275Sbostic.It Li _SC_EXPR_NEST_MAX 8460275SbosticThe maximum number of expressions that can be nested within 8560275Sbosticparenthesis by the 8660275Sbostic.Xr expr 1 8760275Sbosticutility. 8860275Sbostic.It Li _SC_LINE_MAX 8960275SbosticThe maximum length in bytes of a text-processing utility's input 9060275Sbosticline. 9160275Sbostic.It Li _SC_RE_DUP_MAX 9260275SbosticThe maximum number of repeated occurrences of a regular expression 9360275Sbosticpermitted when using interval notation. 9460275Sbostic.It Li _SC_2_VERSION 9560275SbosticThe version of POSIX 1003.2 with which the system attempts to comply. 9660275Sbostic.It Li _SC_2_C_BIND 9760275SbosticReturn 1 if the system's C-language development facilities support the 9860275SbosticC-Language Bindings Option, otherwise \-1. 9960275Sbostic.It Li _SC_2_C_DEV 10060275SbosticReturn 1 if the system supports the C-Language Development Utilities Option, 10160275Sbosticotherwise \-1. 10260275Sbostic.It Li _SC_2_CHAR_TERM 10360275SbosticReturn 1 if the system supports at least one terminal type capable of 10460275Sbosticall operations described in POSIX 1003.2, otherwise \-1. 10560275Sbostic.It Li _SC_2_FORT_DEV 10660275SbosticReturn 1 if the system supports the FORTRAN Development Utilities Option, 10760275Sbosticotherwise \-1. 10860275Sbostic.It Li _SC_2_FORT_RUN 10960275SbosticReturn 1 if the system supports the FORTRAN Runtime Utilities Option, 11060275Sbosticotherwise \-1. 11160275Sbostic.It Li _SC_2_LOCALEDEF 11260275SbosticReturn 1 if the system supports the creation of locales, otherwise \-1. 11360275Sbostic.It Li _SC_2_SW_DEV 11460275SbosticReturn 1 if the system supports the Software Development Utilities Option, 11560275Sbosticotherwise \-1. 11660275Sbostic.It Li _SC_2_UPE 11760275SbosticReturn 1 if the system supports the User Portability Utilities Option, 11860275Sbosticotherwise \-1. 11960275Sbostic.El 12060275Sbostic.Sh RETURN VALUES 12160275SbosticIf the call to 12260275Sbostic.Nm sysconf 12360275Sbosticis not successful, \-1 is returned and 12460275Sbostic.Va errno 12560275Sbosticis set appropriately. 126*66958SbosticOtherwise, if the variable is associated with functionality that is not 12760275Sbosticsupported, \-1 is returned and 12860275Sbostic.Va errno 12960275Sbosticis not modified. 13060275SbosticOtherwise, the current variable value is returned. 13160275Sbostic.Sh ERRORS 13260275SbosticThe 13360275Sbostic.Fn sysconf 13460275Sbosticfunction may fail and set 13560275Sbostic.Va errno 13660275Sbosticfor any of the errors specified for the library functions 13760275Sbostic.Xr sysctl 3 . 13865099SmckusickIn addition, the following error may be reported: 13960275Sbostic.Bl -tag -width Er 14060275Sbostic.It Bq Er EINVAL 14160275SbosticThe value of the 14260275Sbostic.Fa name 14360275Sbosticargument is invalid. 14460275Sbostic.Sh SEE ALSO 14560275Sbostic.Xr sysctl 3 14663772Smckusick.Sh BUGS 14763772SmckusickThe value for _SC_STREAM_MAX is a minimum maximum, and required to be 14863772Smckusickthe same as ANSI C's FOPEN_MAX, so the returned value is a ridiculously 14963772Smckusicksmall and misleading number. 15063772Smckusick.Sh STANDARDS 15163772SmckusickThe 15263772Smckusick.Fn sysconf 15363772Smckusickfunction conforms to 15463772Smckusick.St -p1003.1-88 . 15560275Sbostic.Sh HISTORY 15660275SbosticThe 15760275Sbostic.Nm sysconf 15860275Sbosticfunction first appeared in 4.4BSD. 159