*** UNIX MANUAL PAGE BROWSER ***

confstr(3) Library Functions Manual confstr(3) NAME confstr - Determines the current value of a specified system variable defined by a string value LIBRARY Standard C Library (libc.so, libc.a) SYNOPSIS #include <unistd.h> size_t confstr( int name, char *buf, size_t len); STANDARDS Interfaces documented on this reference page conform to industry stan- dards as follows: confstr(): XPG4, XPG4-UNIX Refer to the standards(5) reference page for more information about in- dustry standards and associated tags. PARAMETERS Specifies the system variable setting to be returned. Valid values for the name parameter are defined in the unistd.h header file. The stan- dard name value is _CS_PATH. Points to the buffer into which the conf- str function copies the name value. Specifies the size of the buffer storing the name value. DESCRIPTION The confstr() function allows an application to determine the current setting of certain system parameters, limits, or options that are de- fined by a string value. The function is mainly used by applications to find the system default value for the PATH environment variable. If the following conditions are true, then the confstr() function copies that value into a len-byte buffer pointed to by the buf parame- ter: The len parameter is not 0 (zero) The name parameter has a system- defined value The buf parameter is not a null pointer If the string to be returned is longer than len bytes, including the terminating null, then the confstr() function truncates the string to len-1 bytes and adds a terminating null to the result. The application can detect that the string was truncated by comparing the value re- turned by confstr() with the value of len. If the value of the len parameter is set to 0 (zero) or the buf value is NULL, the confstr() function returns the size of the buffer needed to hold the entire system-defined value, but does not copy the string value. EXAMPLES To find out how big a buffer is needed to store the string value of name, enter: confstr(_CS_PATH, NULL, (size_t) 0) The confstr() function returns the size of the buffer necessary. RETURN VALUES If the value specified by the name parameter is system-defined, the confstr() function returns the size of the buffer needed to hold the entire value. If this return value is greater than the specified len value, the string returned as the buf value is truncated. If the specified name value is invalid, a value of 0 (zero) is re- turned, and the errno global variable is set to indicate the error. If the specified name value does not have a system-defined value, the confstr() function returns a value of 0 (zero) and leaves errno un- changed. ERRORS The confstr() function sets errno as follows: The value of the name parameter is invalid. FILES Contains system-defined limits. Contains system-defined environment variables. RELATED INFORMATION Functions: pathconf(2), sysconf(3) Standards: standards(5) delim off confstr(3)