#ident "$URL: svn://elmer/devel/SVN/SDDAS/trunk/libant/EnvPrefix.c $ %D% SwRI"
/*
  EnvPrefix -- prefix string with string from environment
*/

#include <stdio.h>		/* for FILE, etc.       */
#include <stdlib.h>		/* for malloc           */
#include <string.h>		/* for string functions */
#include "ant.h"                /* for GetEnv           */

/*
  EnvDirPrefix -- prefix string with directory string from environment
                  dir string MUST NOT end with '/'
*/
char *
EnvDirPrefix(const char  *envvar,char  *str)
{
  char *envstr;			/* string value of environment variable      */
  char *newstr = NULL;		/* same error convention as GetEnv           */

  envstr = GetEnv(envvar);
  
  if (envstr)
    {
      newstr = (char *) malloc(strlen(envstr)+strlen(str)+2);
      strcpy(newstr,envstr);
      strcat(newstr,"/");
      strcat(newstr,str);
    } else {
	fprintf (stderr, "%s not found in environment!\n", envvar);
    }
  return newstr;
}


/* EnvFopen -- fopen file relative to dir found in environment */
FILE *
EnvFopen(char  *EnvName,char  *filename,char  *type)
{
  char *dir;
  FILE  *fp = NULL;
  char  fullname[256];
  char *path;
  static char *separators=":";

  if (!(path=GetEnv(EnvName)))
    return NULL;

  /* try to open file somewhere on path */
  dir = strtok(path,separators);
  for (; dir; dir = strtok(NULL,separators))
    {
      strcpy(fullname,dir);
      strcat(fullname,"/");
      strcat(fullname,filename);
      fp = fopen(fullname, type);
      if (fp)
	break;
    }

  return fp;
}

/* EnvPrefix -- prefix string with string from environment */
char *
EnvPrefix(char  *envvar,char  *str)
{
  char *envstr;			/* string value of environment variable      */
  char *newstr;

  envstr = GetEnv(envvar);
  if (envstr)
    {
      newstr = (char *) malloc(strlen(envstr)+strlen(str)+1);
      strcpy(newstr,envstr);
      strcat(newstr,str);
    }
  else
    newstr = strdup(str);
  return newstr;
}