FSH_PREVCHAR - Decrement a character pointer

Purpose   

This function provides the mechanism for decrementing a character point, 
taking into account DBCS considerations. 

Calling Sequence   

void far pascal FSH_PREVCHAR(pBeg, ppStr)

char far * pBeg;
char far * far * ppStr;

Where   

pBeg is a pointer to the beginning of a string. 

ppStr is a pointer to the character pointer of a string. 

The value is decremented appropriately upon return. If it is at the 
beginning of a string, the pointer is not decremented. If it points to the 
second byte of a DBCS character, it will be decremented to point to the 
first byte of the character. 
  

Returns   

There are no error returns. 

Remarks   

The FSD is responsible for verifying the string pointer and checking for 
segment boundaries. 

Note:   OS/2 does not validate input parameters. An FSD, therefore, should 
call FSH_PROBEBUF where appropriate.