getconf man page on YellowDog

Man page or keyword search:  
man Server   18644 pages
apropos Keyword Search (all sections)
Output format
YellowDog logo
[printable version]

GETCONF(P)		   POSIX Programmer's Manual		    GETCONF(P)

NAME
       getconf - get configuration values

SYNOPSIS
       getconf [ -v specification ] system_var

       getconf [ -v specification ] path_var pathname

DESCRIPTION
       In  the	first  synopsis	 form,	the getconf utility shall write to the
       standard output the value of the variable specified by  the  system_var
       operand.

       In  the	second	synopsis  form, the getconf utility shall write to the
       standard output the value of the variable specified by the path_var op‐
       erand for the path specified by the pathname operand.

       The  value  of each configuration variable shall be determined as if it
       were obtained by calling the function from which it is  defined	to  be
       available  by  this  volume  of	IEEE Std 1003.1-2001  or by the System
       Interfaces volume of IEEE Std 1003.1-2001 (see the  OPERANDS  section).
       The  value  shall  reflect conditions in the current operating environ‐
       ment.

OPTIONS
       The getconf utility shall conform to the	 Base  Definitions  volume  of
       IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.

       The following option shall be supported:

       -v  specification

	      Indicate a specific specification and version for which configu‐
	      ration variables shall be determined.  If	 this  option  is  not
	      specified,  the  values returned correspond to an implementation
	      default conforming compilation environment.

       If the command:

	      getconf _POSIX_V6_ILP32_OFF32

       does not write "-1\n" or "undefined\n" to standard  output,  then  com‐
       mands of the form:

	      getconf -v POSIX_V6_ILP32_OFF32 ...

       determine  values  for  configuration  variables	 corresponding	to the
       POSIX_V6_ILP32_OFF32 compilation environment specified  in  c99	,  the
       EXTENDED DESCRIPTION.

       If the command:

	      getconf _POSIX_V6_ILP32_OFFBIG

       does  not  write	 "-1\n" or "undefined\n" to standard output, then com‐
       mands of the form:

	      getconf -v POSIX_V6_ILP32_OFFBIG ...

       determine values	 for  configuration  variables	corresponding  to  the
       POSIX_V6_ILP32_OFFBIG  compilation  environment	specified in c99 , the
       EXTENDED DESCRIPTION.

       If the command:

	      getconf _POSIX_V6_LP64_OFF64

       does not write "-1\n" or "undefined\n" to standard  output,  then  com‐
       mands of the form:

	      getconf -v POSIX_V6_LP64_OFF64 ...

       determine  values  for  configuration  variables	 corresponding	to the
       POSIX_V6_LP64_OFF64 compilation environment  specified  in  c99	,  the
       EXTENDED DESCRIPTION.

       If the command:

	      getconf _POSIX_V6_LPBIG_OFFBIG

       does  not  write	 "-1\n" or "undefined\n" to standard output, then com‐
       mands of the form:

	      getconf -v POSIX_V6_LPBIG_OFFBIG ...

       determine values	 for  configuration  variables	corresponding  to  the
       POSIX_V6_LPBIG_OFFBIG  compilation  environment	specified in c99 , the
       EXTENDED DESCRIPTION.

OPERANDS
       The following operands shall be supported:

       path_var
	      A name of a configuration variable. All of the variables in  the
	      Variable	column	of  the table in the DESCRIPTION of the fpath‐
	      conf() function defined  in  the	System	Interfaces  volume  of
	      IEEE Std 1003.1-2001,  without  the  enclosing  braces, shall be
	      supported.  The implementation may add other local variables.

       pathname
	      A pathname for which the variable specified by path_var is to be
	      determined.

       system_var
	      A	 name  of a configuration variable. All of the following vari‐
	      ables shall be supported:

	       * The names in the Variable column of the table in the DESCRIP‐
		 TION  of the sysconf() function in the System Interfaces vol‐
		 ume of IEEE Std 1003.1-2001, except for  the  entries	corre‐
		 sponding    to	   _SC_CLK_TCK,	   _SC_GETGR_R_SIZE_MAX,   and
		 _SC_GETPW_R_SIZE_MAX, without the enclosing braces.

	      For compatibility with earlier versions, the following  variable
	      names shall also be supported:

		     POSIX2_C_BIND
		     POSIX2_C_DEV
		     POSIX2_CHAR_TERM
		     POSIX2_FORT_DEV
		     POSIX2_FORT_RUN
		     POSIX2_LOCALEDEF
		     POSIX2_SW_DEV
		     POSIX2_UPE
		     POSIX2_VERSION

	      and shall be equivalent to the same name prefixed with an under‐
	      score.  This requirement may be removed in a future version.

	       * The names of the symbolic constants used as the name argument
		 of  the confstr() function in the System Interfaces volume of
		 IEEE Std 1003.1-2001, without the _CS_ prefix.

	       * The names of the symbolic constants listed under the headings
		 ``Maximum  Values'' and ``Minimum Values'' in the description
		 of the <limits.h> header in the Base  Definitions  volume  of
		 IEEE Std 1003.1-2001, without the enclosing braces.

	      For  compatibility with earlier versions, the following variable
	      names shall also be supported:

		     POSIX2_BC_BASE_MAX
		     POSIX2_BC_DIM_MAX
		     POSIX2_BC_SCALE_MAX
		     POSIX2_BC_STRING_MAX
		     POSIX2_COLL_WEIGHTS_MAX
		     POSIX2_EXPR_NEST_MAX
		     POSIX2_LINE_MAX
		     POSIX2_RE_DUP_MAX

	      and shall be equivalent to the same name prefixed with an under‐
	      score.  This requirement may be removed in a future version.

       The implementation may add other local values.

STDIN
       Not used.

INPUT FILES
       None.

ENVIRONMENT VARIABLES
       The  following environment variables shall affect the execution of get‐
       conf:

       LANG   Provide a default value for the  internationalization  variables
	      that  are	 unset	or  null.  (See the Base Definitions volume of
	      IEEE Std 1003.1-2001, Section  8.2,  Internationalization	 Vari‐
	      ables  for the precedence of internationalization variables used
	      to determine the values of locale categories.)

       LC_ALL If set to a non-empty string value, override the values  of  all
	      the other internationalization variables.

       LC_CTYPE
	      Determine	 the  locale  for  the	interpretation of sequences of
	      bytes of text data as characters (for  example,  single-byte  as
	      opposed to multi-byte characters in arguments).

       LC_MESSAGES
	      Determine	 the  locale  that should be used to affect the format
	      and contents of diagnostic messages written to standard error.

       NLSPATH
	      Determine the location of message catalogs for the processing of
	      LC_MESSAGES .

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       If  the	specified  variable  is defined on the system and its value is
       described to be available from the confstr() function  defined  in  the
       System  Interfaces  volume  of IEEE Std 1003.1-2001, its value shall be
       written in the following format:

	      "%s\n", <value>

       Otherwise, if the specified variable is	defined	 on  the  system,  its
       value shall be written in the following format:

	      "%d\n", <value>

       If  the	specified  variable  is valid, but is undefined on the system,
       getconf shall write using the following format:

	      "undefined\n"

       If the variable name is invalid or an error occurs,  nothing  shall  be
       written to standard output.

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       None.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

	0     The  specified  variable is valid and information about its cur‐
	      rent state was written successfully.

       >0     An error occurred.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       None.

EXAMPLES
       The following example illustrates the value of {NGROUPS_MAX}:

	      getconf NGROUPS_MAX

       The following example illustrates the value of {NAME_MAX}  for  a  spe‐
       cific directory:

	      getconf NAME_MAX /usr

       The  following  example	shows  how to deal more carefully with results
       that might be unspecified:

	      if value=$(getconf PATH_MAX /usr); then
		  if [ "$value" = "undefined" ]; then
		      echo PATH_MAX in /usr is infinite.
		  else
		      echo PATH_MAX in /usr is $value.
		  fi
	      else
		  echo Error in getconf.
	      fi

       Note that:

	      sysconf(_SC_POSIX_C_BIND);

       and:

	      system("getconf POSIX2_C_BIND");

       in a C program could give different answers. The	 sysconf()  call  sup‐
       plies  a	 value that corresponds to the conditions when the program was
       either compiled or executed, depending on the implementation; the  sys‐
       tem()  call  to getconf always supplies a value corresponding to condi‐
       tions when the program is executed.

RATIONALE
       The original need for this utility, and for the confstr() function, was
       to provide a way of finding the configuration-defined default value for
       the PATH environment variable. Since PATH can be modified by  the  user
       to include directories that could contain utilities replacing the stan‐
       dard utilities, shell scripts need a way to determine  the  system-sup‐
       plied  PATH environment variable value that contains the correct search
       path for the standard utilities. It was later suggested that access  to
       the  other  variables  described in this volume of IEEE Std 1003.1-2001
       could also be useful to applications.

       This functionality of getconf  would  not  be  adequately  subsumed  by
       another command such as:

	      grep var /etc/conf

       because	such a strategy would provide correct values for neither those
       variables that can vary at runtime, nor those that can  vary  depending
       on the path.

       Early  proposal	versions  of  getconf specified exit status 1 when the
       specified variable was valid, but not defined on the system. The output
       string  "undefined"  is	now used to specify this case with exit code 0
       because so many things depend on an exit code of zero when  an  invoked
       utility is successful.

FUTURE DIRECTIONS
       None.

SEE ALSO
       c99  , the Base Definitions volume of IEEE Std 1003.1-2001, <limits.h>,
       the System Interfaces volume of IEEE Std 1003.1-2001, confstr(),	 path‐
       conf(), sysconf(), system()

COPYRIGHT
       Portions	 of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       --  Portable  Operating	System	Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003	by  the	 Institute  of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained	online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group		     2003			    GETCONF(P)
[top]

List of man pages available for YellowDog

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net