macEnv.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "errlog.h"
#include "epicsString.h"
#include "macLib.h"

Include dependency graph for macEnv.c:

Go to the source code of this file.

Functions
char *epicsStdCall	macEnvExpand (const char *str)
	Expand environment variables in a string. More...
char *epicsStdCall	macDefExpand (const char *str, MAC_HANDLE *macros)
	Expands macros and environment variables in a string. More...

Function Documentation

char* epicsStdCall macDefExpand	(	const char *	str,
		MAC_HANDLE *	macros
	)

Expands macros and environment variables in a string.

Returns

Expanded string; NULL if any undefined macros were used.

This routine is similar to macEnvExpand() but allows an optional handle to be passed in that may contain additional macro definitions. These macros are appended to the set of macros from environment variables when expanding the string.

Parameters

str	string to be expanded
macros	opaque handle; may be NULL if only environment variables are to be used

Definition at line 26 of file macEnv.c.

{
    MAC_HANDLE *handle;
    static const char * pairs[] = { "", "environ", NULL, NULL };
    long destCapacity = 128;
    char *dest = NULL;
    int n;

    if (macros) {
        handle = macros;
    } else {
        if (macCreateHandle(&handle, pairs)){
            errlogMessage("macDefExpand: macCreateHandle failed.");
            return NULL;
        }
    }

    do {
        destCapacity *= 2;
        /*
         * Use free/malloc rather than realloc since there's no need to
         * keep the original contents.
         */
        free(dest);
        dest = malloc(destCapacity);
        if(!dest)
            goto done;

        n = macExpandString(handle, str, dest, destCapacity);
    } while (n >= (destCapacity - 1));

    if (n < 0) {
        free(dest);
        dest = NULL;
    } else {
        size_t unused = destCapacity - ++n;

        if (unused >= 20)
            dest = realloc(dest, n);
    }

done:
    if (macros == NULL) {
        if (macDeleteHandle(handle)) {
            errlogMessage("macDefExpand: macDeleteHandle failed.");
        }
    }
    return dest;
}

char* epicsStdCall macEnvExpand

(

const char *

str

)

Expand environment variables in a string.

Returns

Expanded string; NULL if any undefined macros were used.

This routine expands a string which may contain macros that are environment variables. It parses the string looking for such references and passes them to macGetValue() for translation. It uses malloc() to allocate space for the expanded string and returns a pointer to this null-terminated string. It returns NULL if the source string contains any undefined references.

Parameters

str	string to be expanded

Definition at line 20 of file macEnv.c.

{
    return macDefExpand(str, NULL);
}