Guardian Native C Library Calls Reference Manual (G06.28+, H06.04+)

confstr(3) Guardian Native C Library Calls Reference Manual

NAME

confstr - Determines the current value of a speciﬁed system variable deﬁned by a string value

LIBRARY

G-series native Guardian processes: system library

G-series native OSS processes: system library

H-series native Guardian processes: implicit libraries

H-series OSS processes: implicit libraries

SYNOPSIS

#include <unistd.h>

size_t confstr(

int name,

char *buf,

size_t len);

PARAMETERS

name Speciﬁes the system variable for which information is to be returned. The only

value recognized in the OSS implementation is _CS_PATH, which requests the

value for the PATH environment variable.

buf Points to the buffer into which the confstr function copies the name value.

len Speciﬁes the size of the buffer to receive the value corresponding to the name

parameter value.

DESCRIPTION

The confstr() function allows an application to determine the current setting of system parame-

ters, limits, or options that are speciﬁed by the string value in its name parameter.

If all of the following are true:

• The len parameter is not 0 (zero)

• The name parameter has a system-deﬁned value

• The buf parameter is not a null pointer

then the confstr() function copies that value into a buffer of len bytes pointed to by the buf

parameter.

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 returned by the

confstr() function with the value of the len parameter.

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 value of the len parameter is 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.

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