/* * File: invert.c * -------------- * This file implements a function InvertName(result, name) * that takes a name in standard order (first middle last) and * returns a new string in inverted order (last, first middle), * which makes it easier to alphabetize the names.  The test * program reads in names and prints out their inverted form, * stopping when a blank line is entered. */#include <stdio.h>#include <string.h>#include "genlib.h"#include "simpio.h"/* * Constant * -------- * MaxName -- Maximum number of characters in a name */#define MaxName 40/* Private function prototypes */static void InvertName(char result[], char name[]);/* Main program */main(){    char *standardName;    char invertedName[MaxName+1];    printf("This program converts a name in standard order\n");    printf("into inverted order with the last name first.\n");    printf("Indicate the end of input with a blank line.\n");    while (TRUE) {        printf("Name: ");        standardName = GetLine();        if (strlen(standardName) == 0) break;        InvertName(invertedName, standardName);        printf("%s\n", invertedName);    }}/* * Function: InvertName * Usage: InvertName(result, name); * -------------------------------- * This function inverts a name from its standard order * *     First Middle Last * * into inverted order, which is * *     Last, First Middle * * The client must supply an output array called result in which * the inverted name will be stored.  That array must contain * at least MaxName character positions, plus one for a * terminating null character.  If storing the inverted name * would exceed that limit, the function generates an error. * The output is always one character longer than the input * because of the comma, so it is possible to determine the * output length immediately. * * The last name is assumed to consist of all characters in the * name string following the last space character.  If there are * no space characters in the word, the entire name is copied to * the destination array unchanged. */static void InvertName(char result[], char name[]){    int len;    char *sptr;    len = strlen(name);    sptr = strrchr(name, ' ');    if (sptr != NULL) len++;    if (len > MaxName) Error("Name too long");    if (sptr == NULL) {        strcpy(result, name);    } else {        strcpy(result, sptr + 1);        strcat(result, ", ");        strncat(result, name, sptr - name);        result[len] = '\0';    }}