Commit 52eb352e authored by A. Wilcox's avatar A. Wilcox 🦊
Browse files

Add our first utility, getconf(1)

parent 3fbd8c32
.Dd April 9, 2016
.Dt GETCONF 1 "Base Commands Manual"
.Os "Adélie Linux"
.Sh NAME
.Nm getconf
.Nd get system configuration values
.Sh SYNOPSIS
.Nm
.Op Fl v Ar specification
.Ar system_var
.Nm
.Op Fl v Ar specification
.Ar path_var
.Ar pathname
.Sh DESCRIPTION
In the first form, the
.Nm
utility prints the value of the system variable specified by
.Ar system_var
on the currently running system, under the specification given for the
.Fl v
argument if specified.
Valid system variables are one of the following:
.Bl -bullet -offset indent -compact
.It
The variable name of a valid parameter to the
.Xr sysconf 3
function as specified in
.St -p1003.1-2008 ,
excluding braces. The variables
.Dq _SC_CLK_TCK ,
.Dq _SC_GETGR_R_SIZE_MAX ,
and
.Dq _SC_GETPW_R_SIZE_MAX
are not supported.
.It
A valid parameter to the
.Xr confstr 3
function as specified in
.St -p1003.1-2008 ,
excluding the
.Dq _CS_
prefix.
.It
A constant listed under the
.Dq Maximum Values
or
.Dq Minimum Values
section of the
.Aq Pa limits.h
header as specified in
.St -p1003.1-2008 ,
excluding braces.
.El
In the second form, the
.Nm
utility prints the value of the path variable specified by
.Ar path_var
for the path specified by
.Ar pathname
on the currently running system, under the specification given for the
.Fl v
argument if specified.
Valid path variables are those accepted by the
.Xr fpathconf 3
function as specified in
.St -p1003.1-2008 ,
exluding braces.
.Sh OPTIONS
.Bl -tag
.It -v
Indicates the specification to use. Currently, this option is unsupported and
will be ignored.
.El
.Sh DIAGNOSTICS
.Ex -std
.Sh SEE ALSO
.Xr confstr 3 ,
.Xr fpathconf 3 ,
.Xr sysconf 3 .
.Sh STANDARDS
The eventual goal for the
.Nm
utility is full conformance to
.St -p1003.1 2013 Edition.
.Sh AUTHORS
.An A. Wilcox
.Aq awilfox@adelielinux.org
.Sh BUGS
The
.Fl v
argument is not currently handled correctly.
.Pp
.Ar path_var
variables are not yet supported.
/*
* getconf - get important system configuration values from the shell.
* Copyright (c) 2016 Adélie Linux Team. All rights reserved.
* Licensed under the NCSA open source license.
* See LICENSE file included with this source for more information.
*/
#include <errno.h> /* errno */
#include <limits.h> /* limit_vars */
#include <stdbool.h> /* bool type and true/false */
#include <stdio.h> /* stderr, fprintf */
#include <stdlib.h> /* malloc, free */
#include <string.h> /* strlen */
#include <strings.h> /* strcasecmp */
#include <unistd.h> /* sysconf + _SC friends, confstr + _CS friends */
typedef struct variable_mapping
{
const char *variable;
const int value;
} var_map_t;
/* For variables that are valid, but undefined in this implementation */
#define _UNDEFINED_VARIABLE_ 0x7FEEDFEE
const var_map_t sysconf_vars[] = {
/* max */
{ "AIO_LISTIO_MAX", _SC_AIO_LISTIO_MAX },
{ "AIO_MAX", _SC_AIO_MAX },
#if defined(_SC_AIO_PRIO_DELTA_MAX)
{ "AIO_PRIO_DELTA_MAX", _SC_AIO_PRIO_DELTA_MAX },
#else /* NetBSD */
{ "AIO_PRIO_DELTA_MAX", _UNDEFINED_VARIABLE_ },
#endif
{ "ARG_MAX", _SC_ARG_MAX },
{ "ATEXIT_MAX", _SC_ATEXIT_MAX },
{ "BC_BASE_MAX", _SC_BC_BASE_MAX },
{ "BC_DIM_MAX", _SC_BC_DIM_MAX },
{ "BC_SCALE_MAX", _SC_BC_SCALE_MAX },
{ "BC_STRING_MAX", _SC_BC_STRING_MAX },
{ "CHILD_MAX", _SC_CHILD_MAX },
{ "COLL_WEIGHTS_MAX", _SC_COLL_WEIGHTS_MAX },
#if defined(_SC_DELAYTIMER_MAX)
{ "DELAYTIMER_MAX", _SC_DELAYTIMER_MAX },
#else /* NetBSD */
{ "DELAYTIMER_MAX", _UNDEFINED_VARIABLE_ },
#endif
{ "EXPR_NEST_MAX", _SC_EXPR_NEST_MAX },
{ "HOST_NAME_MAX", _SC_HOST_NAME_MAX },
{ "IOV_MAX", _SC_IOV_MAX },
{ "LINE_MAX", _SC_LINE_MAX },
{ "LOGIN_NAME_MAX", _SC_LOGIN_NAME_MAX },
{ "NGROUPS_MAX", _SC_NGROUPS_MAX },
{ "MQ_OPEN_MAX", _SC_MQ_OPEN_MAX },
{ "MQ_PRIO_MAX", _SC_MQ_PRIO_MAX },
{ "OPEN_MAX", _SC_OPEN_MAX },
{ "PAGE_SIZE", _SC_PAGE_SIZE },
{ "PAGESIZE", _SC_PAGESIZE },
{ "PTHREAD_DESTRUCTOR_ITERATIONS", _SC_THREAD_DESTRUCTOR_ITERATIONS },
{ "PTHREAD_KEYS_MAX", _SC_THREAD_KEYS_MAX },
{ "PTHREAD_STACK_MIN", _SC_THREAD_STACK_MIN },
{ "PTHREAD_THREADS_MAX", _SC_THREAD_THREADS_MAX },
{ "RE_DUP_MAX", _SC_RE_DUP_MAX },
#if defined(_SC_RTSIG_MAX)
{ "RTSIG_MAX", _SC_RTSIG_MAX },
#else /* NetBSD */
{ "RTSIG_MAX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_SEM_NSEMS_MAX)
{ "SEM_NSEMS_MAX", _SC_SEM_NSEMS_MAX },
#else /* NetBSD */
{ "SEM_NSEMS_MAX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_SEM_VALUE_MAX)
{ "SEM_VALUE_MAX", _SC_SEM_VALUE_MAX },
#else /* NetBSD */
{ "SEM_VALUE_MAX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_SIGQUEUE_MAX)
{ "SIGQUEUE_MAX", _SC_SIGQUEUE_MAX },
#else /* NetBSD */
{ "SIGQUEUE_MAX", _UNDEFINED_VARIABLE_ },
#endif
{ "STREAM_MAX", _SC_STREAM_MAX },
{ "SYMLOOP_MAX", _SC_SYMLOOP_MAX },
#if defined(_SC_TIMER_MAX)
{ "TIMER_MAX", _SC_TIMER_MAX },
#else /* NetBSD */
{ "TIMER_MAX", _UNDEFINED_VARIABLE_ },
#endif
{ "TTY_NAME_MAX", _SC_TTY_NAME_MAX },
{ "TZNAME_MAX", _SC_TZNAME_MAX },
/* POSIX */
#if defined(_SC_ADVISORY_INFO)
{ "_POSIX_ADVISORY_INFO", _SC_ADVISORY_INFO },
#else /* NetBSD */
{ "_POSIX_ADVISORY_INFO", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_BARRIERS", _SC_BARRIERS },
{ "_POSIX_ASYNCHRONOUS_IO", _SC_ASYNCHRONOUS_IO },
{ "_POSIX_CLOCK_SELECTION", _SC_CLOCK_SELECTION },
#if defined(_SC_CPUTIME)
{ "_POSIX_CPUTIME", _SC_CPUTIME },
#else /* NetBSD */
{ "_POSIX_CPUTIME", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_FSYNC", _SC_FSYNC },
#if defined(_SC_IPV6)
{ "_POSIX_IPV6", _SC_IPV6 },
#else /* NetBSD */
{ "_POSIX_IPV6", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_JOB_CONTROL", _SC_JOB_CONTROL },
{ "_POSIX_MAPPED_FILES", _SC_MAPPED_FILES },
{ "_POSIX_MEMLOCK", _SC_MEMLOCK },
{ "_POSIX_MEMLOCK_RANGE", _SC_MEMLOCK_RANGE },
{ "_POSIX_MEMORY_PROTECTION", _SC_MEMORY_PROTECTION },
{ "_POSIX_MESSAGE_PASSING", _SC_MESSAGE_PASSING },
{ "_POSIX_MONOTONIC_CLOCK", _SC_MONOTONIC_CLOCK },
#if defined(_SC_PRIORITIZED_IO)
{ "_POSIX_PRIORITIZED_IO", _SC_PRIORITIZED_IO },
#else /* NetBSD */
{ "_POSIX_PRIORITIZED_IO", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_PRIORITY_SCHEDULING", _SC_PRIORITY_SCHEDULING },
#if defined(_SC_RAW_SOCKETS)
{ "_POSIX_RAW_SOCKETS", _SC_RAW_SOCKETS },
#else /* NetBSD */
{ "_POSIX_RAW_SOCKETS", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_READER_WRITER_LOCKS", _SC_READER_WRITER_LOCKS },
#if defined(_SC_REALTIME_SIGNALS)
{ "_POSIX_REALTIME_SIGNALS", _SC_REALTIME_SIGNALS },
#else /* NetBSD */
{ "_POSIX_REALTIME_SIGNALS", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_REGEXP", _SC_REGEXP },
{ "_POSIX_SAVED_IDS", _SC_SAVED_IDS },
{ "_POSIX_SEMAPHORES", _SC_SEMAPHORES },
#if defined(_SC_SHARED_MEMORY_OBJECTS)
{ "_POSIX_SHARED_MEMORY_OBJECTS", _SC_SHARED_MEMORY_OBJECTS },
#else /* NetBSD */
{ "_POSIX_SHARED_MEMORY_OBJECTS", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_SHELL", _SC_SHELL },
{ "_POSIX_SPAWN", _SC_SPAWN },
{ "_POSIX_SPIN_LOCKS", _SC_SPIN_LOCKS },
#if defined(_SC_SPORADIC_SERVER)
{ "_POSIX_SPORADIC_SERVER", _SC_SPORADIC_SERVER },
#else /* NetBSD */
{ "_POSIX_SPORADIC_SERVER", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_SS_REPL_MAX)
{ "_POSIX_SS_REPL_MAX", _SC_SS_REPL_MAX },
#else /* FreeBSD */
{ "_POSIX_SS_REPL_MAX", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_SYNCHRONIZED_IO", _SC_SYNCHRONIZED_IO },
{ "_POSIX_THREAD_ATTR_STACKADDR", _SC_THREAD_ATTR_STACKADDR },
{ "_POSIX_THREAD_ATTR_STACKSIZE", _SC_THREAD_ATTR_STACKSIZE },
#if defined(_SC_THREAD_CPUTIME)
{ "_POSIX_THREAD_CPUTIME", _SC_THREAD_CPUTIME },
#else /* NetBSD */
{ "_POSIX_THREAD_CPUTIME", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_THREAD_PRIO_INHERIT", _SC_THREAD_PRIO_INHERIT },
{ "_POSIX_THREAD_PRIO_PROTECT", _SC_THREAD_PRIO_PROTECT },
{ "_POSIX_THREAD_PRIO_PROTECT", _UNDEFINED_VARIABLE_ },
{ "_POSIX_THREAD_PRIORITY_SCHEDULING", _SC_THREAD_PRIORITY_SCHEDULING },
{ "_POSIX_THREAD_PROCESS_SHARED", _SC_THREAD_PROCESS_SHARED },
#if defined(_SC_THREAD_ROBUST_PRIO_INHERIT)
{ "_POSIX_THREAD_ROBUST_PRIO_INHERIT", _SC_THREAD_ROBUST_PRIO_INHERIT },
#else /* FreeBSD */
{ "_POSIX_THREAD_ROBUST_PRIO_INHERIT", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_THREAD_ROBUST_PRIO_PROTECT)
{ "_POSIX_THREAD_ROBUST_PRIO_PROTECT", _SC_THREAD_ROBUST_PRIO_PROTECT },
#else /* FreeBSD */
{ "_POSIX_THREAD_ROBUST_PRIO_PROTECT", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_THREAD_SAFE_FUNCTIONS", _SC_THREAD_SAFE_FUNCTIONS },
#if defined(_SC_THREAD_SPORADIC_SERVER)
{ "_POSIX_THREAD_SPORADIC_SERVER", _SC_THREAD_SPORADIC_SERVER },
#else /* NetBSD */
{ "_POSIX_THREAD_SPORADIC_SERVER", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_THREADS", _SC_THREADS },
#if defined(_SC_TIMEOUTS)
{ "_POSIX_TIMEOUTS", _SC_TIMEOUTS },
#else /* NetBSD */
{ "_POSIX_TIMEOUTS", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_TIMERS", _SC_TIMERS },
#if defined(_SC_TRACE)
{ "_POSIX_TRACE", _SC_TRACE },
#else /* NetBSD */
{ "_POSIX_TRACE", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TRACE_EVENT_FILTER)
{ "_POSIX_TRACE_EVENT_FILTER", _SC_TRACE_EVENT_FILTER },
#else /* NetBSD */
{ "_POSIX_TRACE_EVENT_FILTER", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TRACE_EVENT_NAME_MAX)
{ "_POSIX_TRACE_EVENT_NAME_MAX", _SC_TRACE_EVENT_NAME_MAX },
#else /* FreeBSD */
{ "_POSIX_TRACE_EVENT_NAME_MAX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TRACE_INHERIT)
{ "_POSIX_TRACE_INHERIT", _SC_TRACE_INHERIT },
#else /* NetBSD */
{ "_POSIX_TRACE_INHERIT", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TRACE_LOG)
{ "_POSIX_TRACE_LOG", _SC_TRACE_LOG },
#else /* NetBSD */
{ "_POSIX_TRACE_LOG", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TRACE_NAME_MAX)
{ "_POSIX_TRACE_NAME_MAX", _SC_TRACE_NAME_MAX },
#else /* FreeBSD */
{ "_POSIX_TRACE_NAME_MAX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TRACE_SYS_MAX)
{ "_POSIX_TRACE_SYS_MAX", _SC_TRACE_SYS_MAX },
#else /* FreeBSD */
{ "_POSIX_TRACE_SYS_MAX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TRACE_USER_EVENT_MAX)
{ "_POSIX_TRACE_USER_EVENT_MAX", _SC_TRACE_USER_EVENT_MAX },
#else /* FreeBSD */
{ "_POSIX_TRACE_USER_EVENT_MAX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_TYPED_MEMORY_OBJECTS)
{ "_POSIX_TYPED_MEMORY_OBJECTS", _SC_TYPED_MEMORY_OBJECTS },
#else /* NetBSD */
{ "_POSIX_TYPED_MEMORY_OBJECTS", _UNDEFINED_VARIABLE_ },
#endif
{ "_POSIX_VERSION", _SC_VERSION },
#if defined(_SC_V7_ILP32_OFF32)
{ "_POSIX_V7_ILP32_OFF32", _SC_V7_ILP32_OFF32 },
#else /* FreeBSD */
{ "_POSIX_V7_ILP32_OFF32", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_V7_ILP32_OFFBIG)
{ "_POSIX_V7_ILP32_OFFBIG", _SC_V7_ILP32_OFFBIG },
#else /* FreeBSD */
{ "_POSIX_V7_ILP32_OFFBIG", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_V7_LP64_OFF64)
{ "_POSIX_V7_LP64_OFF64", _SC_V7_LP64_OFF64 },
#else /* FreeBSD */
{ "_POSIX_V7_LP64_OFF64", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_V7_LPBIG_OFFBIG)
{ "_POSIX_V7_LPBIG_OFFBIG", _SC_V7_LPBIG_OFFBIG },
#else /* FreeBSD */
{ "_POSIX_V7_LPBIG_OFFBIG", _UNDEFINED_VARIABLE_ },
#endif
/* POSIX.2 */
{ "_POSIX2_C_BIND", _SC_2_C_BIND },
{ "_POSIX2_C_DEV", _SC_2_C_DEV },
{ "_POSIX2_CHAR_TERM", _SC_2_CHAR_TERM },
{ "_POSIX2_FORT_DEV", _SC_2_FORT_DEV },
{ "_POSIX2_FORT_RUN", _SC_2_FORT_RUN },
{ "_POSIX2_LOCALEDEF", _SC_2_LOCALEDEF },
{ "_POSIX2_PBS", _SC_2_PBS },
{ "_POSIX2_PBS_ACCOUNTING", _SC_2_PBS_ACCOUNTING },
{ "_POSIX2_PBS_CHECKPOINT", _SC_2_PBS_CHECKPOINT },
{ "_POSIX2_PBS_LOCATE", _SC_2_PBS_LOCATE },
{ "_POSIX2_PBS_MESSAGE", _SC_2_PBS_MESSAGE },
{ "_POSIX2_PBS_TRACK", _SC_2_PBS_TRACK },
{ "_POSIX2_SW_DEV", _SC_2_SW_DEV },
{ "_POSIX2_UPE", _SC_2_UPE },
{ "_POSIX2_VERSION", _SC_2_VERSION },
/* X/Open */
#if defined(_SC_XOPEN_CRYPT)
{ "_XOPEN_CRYPT", _SC_XOPEN_CRYPT },
#else /* NetBSD */
{ "_XOPEN_CRYPT", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_XOPEN_ENH_I18N)
{ "_XOPEN_ENH_I18N", _SC_XOPEN_ENH_I18N },
#else /* NetBSD */
{ "_XOPEN_ENH_I18N", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_XOPEN_REALTIME)
{ "_XOPEN_REALTIME", _SC_XOPEN_REALTIME },
#else /* NetBSD */
{ "_XOPEN_REALTIME", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_XOPEN_REALTIME_THREADS)
{ "_XOPEN_REALTIME_THREADS", _SC_XOPEN_REALTIME_THREADS },
#else /* NetBSD */
{ "_XOPEN_REALTIME_THREADS", _UNDEFINED_VARIABLE_ },
#endif
{ "_XOPEN_SHM", _SC_XOPEN_SHM },
#if defined(_SC_XOPEN_STREAMS)
{ "_XOPEN_STREAMS", _SC_XOPEN_STREAMS },
#else /* NetBSD */
{ "_XOPEN_STREAMS", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_XOPEN_UNIX)
{ "_XOPEN_UNIX", _SC_XOPEN_UNIX },
#else /* NetBSD */
{ "_XOPEN_UNIX", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_XOPEN_UUCP)
{ "_XOPEN_UUCP", _SC_XOPEN_UUCP },
#else /* glibc */
{ "_XOPEN_UUCP", _UNDEFINED_VARIABLE_ },
#endif
#if defined(_SC_XOPEN_VERSION)
{ "_XOPEN_VERSION", _SC_XOPEN_VERSION }
#else /* NetBSD */
{ "_XOPEN_VERSION", _UNDEFINED_VARIABLE_ }
#endif
};
const int sysvar_count = sizeof(sysconf_vars) / sizeof(sysconf_vars[0]);
const var_map_t confstr_vars[] = {
{ "PATH", _CS_PATH },
#if defined(_CS_V7_ENV)
{ "V7_ENV", _CS_V7_ENV }
#else
{ "V7_ENV", _UNDEFINED_VARIABLE_ }
#endif
};
const int confstr_count = sizeof(confstr_vars) / sizeof(confstr_vars[0]);
const var_map_t limit_vars[] = {
{ "_POSIX_AIO_LISTIO_MAX", _POSIX_AIO_LISTIO_MAX },
{ "_POSIX_AIO_MAX", _POSIX_AIO_MAX },
{ "_POSIX_ARG_MAX", _POSIX_ARG_MAX },
{ "_POSIX_CHILD_MAX", _POSIX_CHILD_MAX },
{ "_POSIX_DELAYTIMER_MAX", _POSIX_DELAYTIMER_MAX },
{ "_POSIX_HOST_NAME_MAX", _POSIX_HOST_NAME_MAX },
{ "_POSIX_LINK_MAX", _POSIX_LINK_MAX },
{ "_POSIX_LOGIN_NAME_MAX", _POSIX_LOGIN_NAME_MAX },
{ "_POSIX_MAX_CANON", _POSIX_MAX_CANON },
{ "_POSIX_MAX_INPUT", _POSIX_MAX_INPUT },
{ "_POSIX_NAME_MAX", _POSIX_NAME_MAX },
{ "_POSIX_NGROUPS_MAX", _POSIX_NGROUPS_MAX },
{ "_POSIX_OPEN_MAX", _POSIX_OPEN_MAX },
{ "_POSIX_PATH_MAX", _POSIX_PATH_MAX },
{ "_POSIX_PIPE_BUF", _POSIX_PIPE_BUF },
{ "_POSIX_RE_DUP_MAX", _POSIX_RE_DUP_MAX },
{ "_POSIX_RTSIG_MAX", _POSIX_RTSIG_MAX },
{ "_POSIX_SEM_NSEMS_MAX", _POSIX_SEM_NSEMS_MAX },
{ "_POSIX_SEM_VALUE_MAX", _POSIX_SEM_VALUE_MAX },
{ "_POSIX_SIGQUEUE_MAX", _POSIX_SIGQUEUE_MAX },
{ "_POSIX_SSIZE_MAX", _POSIX_SSIZE_MAX },
{ "_POSIX_STREAM_MAX", _POSIX_STREAM_MAX },
{ "_POSIX_SYMLINK_MAX", _POSIX_SYMLINK_MAX },
{ "_POSIX_SYMLOOP_MAX", _POSIX_SYMLOOP_MAX },
{ "_POSIX_THREAD_DESTRUCTOR_ITERATIONS",
_POSIX_THREAD_DESTRUCTOR_ITERATIONS },
{ "_POSIX_THREAD_KEYS_MAX", _POSIX_THREAD_KEYS_MAX },
{ "_POSIX_THREAD_THREADS_MAX", _POSIX_THREAD_THREADS_MAX },
{ "_POSIX_TIMER_MAX", _POSIX_TIMER_MAX },
{ "_POSIX_TTY_NAME_MAX", _POSIX_TTY_NAME_MAX },
{ "_POSIX_TZNAME_MAX", _POSIX_TZNAME_MAX },
{ "_POSIX2_BC_BASE_MAX", _POSIX2_BC_BASE_MAX },
{ "_POSIX2_BC_DIM_MAX", _POSIX2_BC_DIM_MAX },
{ "_POSIX2_BC_SCALE_MAX", _POSIX2_BC_SCALE_MAX },
{ "_POSIX2_BC_STRING_MAX", _POSIX2_BC_STRING_MAX },
{ "_POSIX2_CHARCLASS_NAME_MAX", _POSIX2_CHARCLASS_NAME_MAX },
{ "_POSIX2_COLL_WEIGHTS_MAX", _POSIX2_COLL_WEIGHTS_MAX },
{ "_POSIX2_EXPR_NEST_MAX", _POSIX2_EXPR_NEST_MAX },
{ "_POSIX2_LINE_MAX", _POSIX2_LINE_MAX },
{ "_POSIX2_RE_DUP_MAX", _POSIX2_RE_DUP_MAX }
};
const int limit_count = sizeof(limit_vars) / sizeof(limit_vars[0]);
int do_system_var(char *environment, char *system_var)
{
int var;
if(strlen(environment) != 0)
{
fprintf(stderr, "Unsupported environment: %s\n", environment);
return EINVAL;
}
for(var = 0; var < sysvar_count; var++)
{
long int val;
if(strcasecmp(sysconf_vars[var].variable, system_var) != 0)
continue;
if(sysconf_vars[var].value == _UNDEFINED_VARIABLE_)
{
printf("undefined\n");
return 0;
}
errno = 0;
val = sysconf(sysconf_vars[var].value);
if(errno != 0)
{
/* We know that this is a valid symbol, so don't break
* expectations (see _POSIX_TRACE_LOG in FreeBSD).
*
* Note that POSIX states explicitly that results are
* already unspecified if the value is dependent on an
* unsupported POSIX option. It also indicates that
* *all* variables defined for sysconf *must* return
* a result in getconf. So, I feel this is the
* strictest way to conform.
*/
printf("undefined\n");
return 0;
}
printf("%ld\n", val);
return 0;
}
for(var = 0; var < limit_count; var++)
{
if(strcasecmp(limit_vars[var].variable, system_var) != 0)
continue;
printf("%d\n", limit_vars[var].value);
return 0;
}
for(var = 0; var < confstr_count; var++)
{
size_t str_len;
char *str;
if(strcasecmp(confstr_vars[var].variable, system_var) != 0)
continue;
if(confstr_vars[var].value == _UNDEFINED_VARIABLE_)
{
printf("undefined\n");
return 0;
}
errno = 0;
str_len = confstr(confstr_vars[var].value, NULL, 0);
if(errno != 0 || str_len == 0)
{
/* We know that this is a valid symbol, so don't break
* expectations (see above comment for sysconf).
*/
printf("undefined\n");
return 0;
}
str = malloc(str_len);
confstr(confstr_vars[var].value, str, str_len);
printf("%s\n", str);
free(str);
return 0;
}
fprintf(stderr, "%s: not a recognised system variable\n", system_var);
return EINVAL;
}
int do_path_var(char *environment, char *path_var, char *pathname)
{
return -1;
}
int main(int argc, char *argv[])
{
/* The envrionment passed by -v, if any. Ignored for now. */
char *environment = NULL;
/* An error occurred during argument parsing */
bool arg_error = false;
/* The current argument being parsed */
int arg;
while((arg = getopt(argc, argv, ":v:")) != -1)
{
switch(arg)
{
case 'v':
environment = optarg;
break;
case ':':
fprintf(stderr, "required argument to '-%c' missing\n",
optopt);
arg_error = true;
break;
case '?':
default:
fprintf(stderr, "unrecognised option: '-%c'\n", optopt);
arg_error = true;
break;
}
}
switch(argc - optind)
{
case 1:
return do_system_var(environment, argv[optind++]);
case 2:
return do_path_var(environment, argv[optind], argv[optind+1]);
default:
/* just show usage. */
arg_error = true;
break;
}
if(arg_error)
{
fprintf(stderr, "usage:\n");