/* * File: simpio.c * Version: 1.0 * Last modified on Fri Jul 15 14:10:41 1994 by eroberts * ----------------------------------------------------- * This file implements the simpio.h interface. */#include <stdio.h>#include <string.h>#include "genlib.h"#include "strlib.h"#include "simpio.h"/* * Constants: * ---------- * InitialBufferSize -- Initial buffer size for ReadLine */#define InitialBufferSize 120/* Exported entries *//* * Functions: GetInteger, GetLong, GetReal * --------------------------------------- * These functions first read a line and then call sscanf to * translate the number.  Reading an entire line is essential to * good error recovery, because the characters after the point of * error would otherwise remain in the input buffer and confuse * subsequent input operations.  The sscanf line allows white space * before and after the number but no other extraneous characters. */int GetInteger(void){    string line;    int value;    char termch;    while (TRUE) {        line = GetLine();        switch (sscanf(line, " %d %c", &value, &termch)) {          case 1:            FreeBlock(line);            return (value);          case 2:            printf("Unexpected character: '%c'\n", termch);            break;          default:            printf("Please enter an integer\n");            break;        }        FreeBlock(line);        printf("Retry: ");    }}long GetLong(void){    string line;    long value;    char termch;    while (TRUE) {        line = GetLine();        switch (sscanf(line, " %ld %c", &value, &termch)) {          case 1:            FreeBlock(line);            return (value);          case 2:            printf("Unexpected character: '%c'\n", termch);            break;          default:            printf("Please enter an integer\n");            break;        }        FreeBlock(line);        printf("Retry: ");    }}double GetReal(void){    string line;    double value;    char termch;    while (TRUE) {        line = GetLine();        switch (sscanf(line, " %lf %c", &value, &termch)) {          case 1:            FreeBlock(line);            return (value);          case 2:            printf("Unexpected character: '%c'\n", termch);            break;          default:            printf("Please enter a real number\n");            break;        }        FreeBlock(line);        printf("Retry: ");    }}/* * Function: GetLine * ----------------- * This function is a simple wrapper; all the work is done by * ReadLine. */string GetLine(void){    return (ReadLine(stdin));}/* * Function: ReadLine * ------------------ * This function operates by reading characters from the file * into a dynamically allocated buffer.  If the buffer becomes * full before the end of the line is reached, a new buffer * twice the size of the previous one is allocated. */string ReadLine(FILE *infile){    string line, nline;    int n, ch, size;    n = 0;    size = InitialBufferSize;    line = GetBlock(size + 1);    while ((ch = getc(infile)) != '\n' && ch != EOF) {        if (n == size) {            size *= 2;            nline = (string) GetBlock(size + 1);            strncpy(nline, line, n);            FreeBlock(line);            line = nline;        }        line[n++] = ch;    }    if (n == 0 && ch == EOF) {        FreeBlock(line);        return (NULL);    }    line[n] = '\0';    nline = (string) GetBlock(n + 1);    strcpy(nline, line);    FreeBlock(line);    return (nline);}