debian man page for strvars

STRVARS(3pub)						       C Programmer's Manual						     STRVARS(3pub)

NAME
       strvars - expand variables in string

SYNOPSIS
       #include <publib.h>
       int strvars(char **res, const char *str, char *(*expand)(const char *));

DESCRIPTION
       strvars will replaces references to variables in the string str with the values of the variables.  A reference to a variable is of the form
       $(foo) or $x (where x is a single character, but not $).  A dollar sign is expressed in the string as $$, and will be converted to $ in the
       output.	Memory for the expanded string is allocated dynamically, and *res is set to point to it.

       The values of the variables are fetched using the function expand.  It is given the name of the variable as its argument, and must return a
       pointer to the value, or NULL if that variable doesn't exist.

RETURN VALUE
       strvars will return 0 if successful, or NULL if an error occured (malformed input string, result too big, or unknown variable).

EXAMPLE
       To replace references to environment variables, one would the following.

	    #include <publib.h>
	    #include <stdlib.h>

	    char line[1024];
	    char *res;

	    if (strvars(&res, line, getenv) == NULL)
		errormsg(1, 0, "strvars failed");
	    printf("res = <%s>
", res);

SEE ALSO
       publib(3), getenv(3)

AUTHOR
       Lars Wirzenius (lars.wirzenius@helsinki.fi)

Publib							       C Programmer's Manual						     STRVARS(3pub)