task1

src/simpio.c

+/*
+ * File: simpio.c
+ * Version: 3.0
+ * Last modified on Tue Oct  4 11:24:40 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();
+        if (line == NULL) Error("GetInteger: unexpected end of file");
+        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();
+        if (line == NULL) Error("GetLong: unexpected end of file");
+        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();
+        if (line == NULL) Error("GetReal: unexpected end of file");
+        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);
+}

src/strlib.c

+/*
+ * File: strlib.c
+ * Version: 1.0
+ * Last modified on Fri Jul 15 14:10:41 1994 by eroberts
+ * -----------------------------------------------------
+ * This file implements the strlib.h interface.
+ */
+
+/*
+ * General implementation notes:
+ * -----------------------------
+ * This module implements the strlib library by mapping all
+ * functions into the appropriate calls to the ANSI <string.h>
+ * interface.  The implementations of the individual functions
+ * are all quite simple and do not require individual comments.
+ * For descriptions of the behavior of each function, see the
+ * interface.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "genlib.h"
+#include "strlib.h"
+
+/*
+ * Constant: MaxDigits
+ * -------------------
+ * This constant must be larger than the maximum
+ * number of digits that can appear in a number.
+ */
+
+#define MaxDigits 30
+
+/* Private function prototypes */
+
+static string CreateString(int len);
+
+/* Section 1 -- Basic string operations */
+
+string Concat(string s1, string s2)
+{
+    string s;
+    int len1, len2;
+
+    if (s1 == NULL || s2 == NULL) {
+        Error("NULL string passed to Concat");
+    }
+    len1 = strlen(s1);
+    len2 = strlen(s2);
+    s = CreateString(len1 + len2);
+    strcpy(s, s1);
+    strcpy(s + len1, s2);
+    return (s);
+}
+
+char IthChar(string s, int i)
+{
+    int len;
+
+    if (s == NULL) Error("NULL string passed to IthChar");
+    len = strlen(s);
+    if (i < 0 || i > len) {
+        Error("Index outside of string range in IthChar");
+    }
+    return (s[i]);
+}
+
+string SubString(string s, int p1, int p2)
+{
+    int len;
+    string result;
+
+    if (s == NULL) Error("NULL string passed to SubString");
+    len = strlen(s);
+    if (p1 < 0) p1 = 0;
+    if (p2 >= len) p2 = len - 1;
+    len = p2 - p1 + 1;
+    if (len < 0) len = 0;
+    result = CreateString(len);
+    strncpy(result, s + p1, len);
+    result[len] = '\0';
+    return (result);
+}
+
+string CharToString(char ch)
+{
+    string result;
+
+    result = CreateString(1);
+    result[0] = ch;
+    result[1] = '\0';
+    return (result);
+}
+
+int StringLength(string s)
+{
+    if (s == NULL) Error("NULL string passed to StringLength");
+    return (strlen(s));
+}
+
+string CopyString(string s)
+{
+    string newstr;
+
+    if (s == NULL) Error("NULL string passed to CopyString");
+    newstr = CreateString(strlen(s));
+    strcpy(newstr, s);
+    return (newstr);
+}
+
+/* Section 2 -- String comparison functions */
+
+bool StringEqual(string s1, string s2)
+{
+    if (s1 == NULL || s2 == NULL) {
+        Error("NULL string passed to StringEqual");
+    }
+    return (strcmp(s1, s2) == 0);
+}
+
+int StringCompare(string s1, string s2)
+{
+    if (s1 == NULL || s2 == NULL) {
+        Error("NULL string passed to StringCompare");
+    }
+    return (strcmp(s1, s2));
+}
+
+/* Section 3 -- Search functions */
+
+int FindChar(char ch, string text, int start)
+{
+    char *cptr;
+
+    if (text == NULL) Error("NULL string passed to FindChar");
+    if (start < 0) start = 0;
+    if (start > strlen(text)) return (-1);
+    cptr = strchr(text + start, ch);
+    if (cptr == NULL) return (-1);
+    return ((int) (cptr - text));
+}
+
+int FindString(string str, string text, int start)
+{
+    char *cptr;
+
+    if (str == NULL) Error("NULL pattern string in FindString");
+    if (text == NULL) Error("NULL text string in FindString");
+    if (start < 0) start = 0;
+    if (start > strlen(text)) return (-1);
+    cptr = strstr(text + start, str);
+    if (cptr == NULL) return (-1);
+    return ((int) (cptr - text));
+}
+
+/* Section 4 -- Case-conversion functions */
+
+string ConvertToLowerCase(string s)
+{
+    string result;
+    int i;
+
+    if (s == NULL) {
+        Error("NULL string passed to ConvertToLowerCase");
+    }
+    result = CreateString(strlen(s));
+    for (i = 0; s[i] != '\0'; i++) result[i] = tolower(s[i]);
+    result[i] = '\0';
+    return (result);
+}
+
+string ConvertToUpperCase(string s)
+{
+    string result;
+    int i;
+
+    if (s == NULL) {
+        Error("NULL string passed to ConvertToUpperCase");
+    }
+    result = CreateString(strlen(s));
+    for (i = 0; s[i] != '\0'; i++) result[i] = toupper(s[i]);
+    result[i] = '\0';
+    return (result);
+}
+
+/* Section 5 -- Functions for converting numbers to strings */
+
+string IntegerToString(int n)
+{
+    char buffer[MaxDigits];
+
+    sprintf(buffer, "%d", n);
+    return (CopyString(buffer));
+}
+
+int StringToInteger(string s)
+{
+    int result;
+    char dummy;
+
+    if (s == NULL) {
+        Error("NULL string passed to StringToInteger");
+    }
+    if (sscanf(s, " %d %c", &result, &dummy) != 1) {
+        Error("StringToInteger called on illegal number %s", s);
+    }
+    return (result);
+}
+
+string RealToString(double d)
+{
+    char buffer[MaxDigits];
+
+    sprintf(buffer, "%G", d);
+    return (CopyString(buffer));
+}
+
+double StringToReal(string s)
+{
+    double result;
+    char dummy;
+
+    if (s == NULL) Error("NULL string passed to StringToReal");
+    if (sscanf(s, " %lg %c", &result, &dummy) != 1) {
+        Error("StringToReal called on illegal number %s", s);
+    }
+    return (result);
+}
+
+/* Private functions */
+
+/*
+ * Function: CreateString
+ * Usage: s = CreateString(len);
+ * -----------------------------
+ * This function dynamically allocates space for a string of
+ * len characters, leaving room for the null character at the
+ * end.
+ */
+
+static string CreateString(int len)
+{
+    return ((string) GetBlock(len + 1));
+}