envVarConv2Str.c

/* ---------------------------------------------------------------------------
** This software is in the public domain, furnished "as is", without technical
** support, and with no warranty, express or implied, as to its usefulness for
** any purpose.
**
** envVarConv2Str.c
** read env parameter from pqact.conf and convert it to normal test string
**
** Author: Y.C. Tang
** Modify: Harry Chen
** -------------------------------------------------------------------------*/
#ifdef IDENT_C
static const char* const envVarConv2Str_c_Id =
  "$Id: envVarConv2Str.c,v 1.1 1994/04/29 16:55:55 fxa Exp $";
#endif

#include <stdio.h>
#include <assert.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <signal.h>
#include "ldm.h"
#include "regexp.h"                     /* Henry Spencer's package, not library 
version */
#include "palt.h"
#include "action.h"
#include "ldmprint.h"
#include "atofeedt.h"
#include "alloc.h"
#include "ulog.h"


# define MAXLEN 1024
/* -- AppendStr   ----------------------------------------------------------
** appen each character to the string
** 
** return 0 if sucess
/* -- implementation -------------------------------------------------------
** 
**
**
** -------------------------------------------------------------------------*/
int AppendStr(char *OriStr, char *AppStr)
    {
    if ( AppStr == NULL )
        {
        /* selected environment variable not exist */
        udebug("envVarConv2Str Append string is NULL characters");
        return 0;
        }
    if ( ( strlen(OriStr) + strlen(AppStr) ) >= MAXLEN )
        {
        uerror("envVarConv2Str Append string exceeds maximum length: %d 
characters", MAXLEN);
        return 1;
        }
    else
        {
        strcat(OriStr, AppStr);
        return 0;
        }
    }/*AppendStr*/

/* --envVarConv2Str  -------------------------------------------------------
** Convert enviroment variable to the normal text string
** 
**
/* -- implementation -------------------------------------------------------
** pass in the original string no mater if it has env. Var.
** and return the converted string 
**
** -------------------------------------------------------------------------*/
char *envVarConv2Str(char *instr)
    {
    /* declaration */
    int  instrlen=0, i=0, iret=0;
    static char outstr[MAXLEN+1];
    char varstr[MAXLEN+1];
    char tmpstr[2];
    enum cstate { TEXT, VARSTART, PARVAR, NOPARVAR } state;

    /* check input string length */
    if ( ( instrlen=strlen(instr) ) >= MAXLEN )
        {
        uerror("envVarConv2Str input string exceeds maximum length: %d 
characters", MAXLEN);
        return(NULL);
        }

    /* set initial state */
    varstr[0]=0;
    outstr[0]=0;
    tmpstr[0]=0;
    state=TEXT;

    /* start text expanding loop */
    for ( i=0; i< instrlen; i++ )
        {
        /*
        uinfo("envVarConv2Str processing char : %c", instr[i]);
        */
        switch(state)
            {
            case TEXT :
                /* general text character */
                if ( instr[i] != '$' )
                    {
                    /* general text character */
                    sprintf(tmpstr,"%c",instr[i]);
                    if ( (iret=AppendStr(outstr, tmpstr)) != 0 )
                        return NULL;
                    }
                else
                    {
                    /* environment variable starts */
                    state=VARSTART;
                    }
                break;

            case VARSTART :
                /* environment variable starts */

                if ( instr[i] == '{' )
                    {
                    /* environment variable starts with { */
                    state=PARVAR;
                    }
                else if ( isalpha(instr[i]) || (instr[i] == '_') )
                    {
                    /* environment variable continue */
                    state=NOPARVAR;
                    sprintf(tmpstr,"%c",instr[i]);
                    if ( (iret=AppendStr(varstr, tmpstr)) != 0 )
                        return NULL;
                    }
                else if ( instr[i] == '$' )
                    {
                    /* environment variable is $$ (PID) */
                    state=TEXT;
                    sprintf(varstr,"%d",getppid());
                    if ( (iret=AppendStr(outstr, varstr)) != 0 )
                        return NULL;
                    strcpy(varstr,"");
                    }
                else
                    {
                    /* not an environment variable */
                    state=TEXT;
                    sprintf(varstr,"$%c",instr[i]);
                    if ( (iret=AppendStr(outstr, varstr)) != 0 )
                        return NULL;
                    strcpy(varstr,"");
                    }

                break;

            case NOPARVAR :
                /* environment variable starts with no { */
                if ( isalnum(instr[i]) || (instr[i] == '_') )
                    {
                    /* environment variable continue */
                    sprintf(tmpstr,"%c",instr[i]);
                    if ( (iret=AppendStr(varstr, tmpstr)) != 0 )
                        return NULL;
                    }
                else if ( instr[i] == '$' )
                    {
                    /* environment variable ends with another variable start */
                    state=VARSTART;
                    if ( (iret=AppendStr(outstr,(char *)getenv(varstr))) != 0 )
                        return NULL;
                    strcpy(varstr,"");
                    }
                else if ( instr[i] == ' ' )
                    {
                    /* environment variable ends with blank space */
                    state=TEXT;
                    if ( (iret=AppendStr(outstr,(char *)getenv(varstr))) != 0 )
                         return NULL;
                    if ( (iret=AppendStr(outstr, " ")) != 0 )
                         return NULL;
                    strcpy(varstr,"");
                    }
                else
                    {
                    /* environment variable ends */
                    state=TEXT;
                    if ( (iret=AppendStr(outstr,(char *)getenv(varstr))) != 0 )
                        return NULL;
                    strcpy(varstr,"");
                    sprintf(tmpstr,"%c",instr[i]);
                    if ( (iret=AppendStr(outstr,tmpstr)) != 0 )
                        return NULL;
                    }
                break;

            case PARVAR :
                /* environment variable starts with { */

                if ( instr[i] == '}' )
                    {
                    /* environment variable ends */
                    state=TEXT;
                    if ( (iret=AppendStr(outstr,(char *)getenv(varstr))) != 0 )
                        return NULL;
                    strcpy(varstr,"");
                    }
                else
                    {
                    /* environment variable continue */
                    sprintf(tmpstr,"%c",instr[i]);
                    if ( (iret=AppendStr(varstr,tmpstr)) != 0 )
                        return NULL;
                    }
                break;
            }
        }

    switch(state)
        {
        case PARVAR :
            /* environment variable is not ended yet */
            uerror("envVarConv2Str transform fail");
                return NULL;
            break;

        case NOPARVAR :
            /* environment ended at the end of the string */
            if ( (iret=AppendStr(outstr,(char *)getenv(varstr))) != 0 )
                return NULL;
            udebug("envVarConv2Str transform ok");
            break;

        case VARSTART :
            /* $ ended at the end of the string */
            sprintf(tmpstr,"$",instr[i]);
            if ( (iret=AppendStr(outstr,tmpstr)) != 0 )
                return NULL;
            udebug("envVarConv2Str transform ok,output string:\"%s\"", outstr);
            break;

        default :
            break;
        }
    return outstr;
    }



===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================