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CONFSTR(3)		     Library Functions Manual		      CONFSTR(3)

NAME
     confstr -- get string-valued configurable variables

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     size_t
     confstr(int name, char *buf, size_t len);

DESCRIPTION
     This  interface  is  specified by IEEE Std 1003.1-2001 ("POSIX.1").  A more
     flexible (but non-portable) interface is provided by sysctl(3).

     The confstr() function provides a method for applications to get configura-
     tion defined string values.  Shell programmers needing access to these  pa-
     rameters should use the getconf(1) utility.

     The  name	argument  specifies the system variable to be queried.	Symbolic
     constants for each name value are found in  the  include  file  <unistd.h>.
     The  len  argument specifies the size of the buffer referenced by the argu-
     ment buf.	If len is non-zero, buf is a non-null pointer, and  name  has  a
     value,  up  to  len  - 1 bytes of the value are copied into the buffer buf.
     The copied value is always null terminated.

     The available values are as follows:

     _CS_PATH
	     Return a value for the PATH environment variable that finds all the
	     standard utilities.

RETURN VALUES
     If the call to confstr() is not successful, 0 is returned and errno is  set
     appropriately.   Otherwise,  if  the variable does not have a configuration
     defined value, 0 is returned and errno is	not  modified.	 Otherwise,  the
     buffer  size  needed  to hold the entire configuration-defined value is re-
     turned.  If this size is greater than the argument len, the string  in  buf
     was truncated.

ERRORS
     The  confstr() function may fail and set errno for any of the errors speci-
     fied for the library functions malloc(3) and sysctl(3).

     In addition, the following errors may be reported:

     [EINVAL]		The value of the name argument is invalid.

SEE ALSO
     getconf(1), pathconf(2), sysconf(3), sysctl(3)

HISTORY
     The confstr() function first appeared in 4.4BSD.

FreeBSD 15.1			December 3, 2006		      CONFSTR(3)
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