Initial commit

Labs/Lab4/Lec10src/Strings.h

@@ -0,0 +1,19 @@
+
+#ifndef STRINGS_H
+#define STRINGS_H
+
+// a cover function for malloc()
+// malloc and return memory for a string of stringsize characters
+// return (char*)NULL on failure
+char* mallocString(int stringsize);
+
+// just a cover function for free()
+void freeString(char* s);
+
+// create a duplicate string of s
+// return it
+// return (char*)NULL on failure
+// should call mallocString(), and then strcpy()
+char* duplicateString(char* s);
+
+#endif

Labs/Lab4/Lec10src/arrayOfStrings.c

@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+int main(int argc, char* argv[]){
+
+	char** stringList;
+
+	// allocate an array of pointers to strings (each string is a char*)
+	stringList = (char**) malloc(sizeof(char*) * argc);
+	if(stringList == (char**)NULL){
+		fprintf(stderr,"Memory failure, terminating");
+		return EXIT_FAILURE;
+	}
+	for(int i=0; i<argc; i++){
+		// allocate the string
+		stringList[i] = (char*) malloc( sizeof(char)* (strlen(argv[i]) +1) );
+		if(stringList[i] == (char*)NULL){
+			fprintf(stderr,"Memory failure, terminating");
+			for(int j=0; j<i; i++){
+				free(stringList[j]);
+			}
+			free(stringList);
+			return EXIT_FAILURE;
+		}
+		// copy commandline arguement
+		strcpy(stringList[i], argv[i]);
+	}
+
+	// Did we do it? Can we print them out?
+	for(int i=0; i<argc; i++){
+		printf("%s\n", stringList[i]);
+	}
+
+	// Cleaning up after ourselves, from the end to the beginning
+	for(int i=0; i<argc; i++){
+		free(stringList[i]);
+	}
+	free(stringList);
+
+	return EXIT_SUCCESS;
+}
+
+

Labs/Lab4/Lec10src/arrayVals.c

@@ -0,0 +1,56 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MAXVALS 4
+void arrayVals(int iN, int* arr, int val);
+
+int main(void){
+
+	int iErr;
+	int iVal;
+	int a[MAXVALS];
+	char* prompt = "value: ";
+	
+	printf("%s",prompt);
+	iErr = scanf("%d", &iVal);
+	if(iErr != 1){
+		fprintf(stderr, "Unable to read value\n");
+		return EXIT_FAILURE;
+	}
+
+	arrayVals(MAXVALS, a, iVal);
+	printf("-------------------------------------------\n");
+	printf("main prompt (char*):\t%p\n", &prompt);
+	printf("main a (int[MAXVALS]):\t%p\n", a);
+	printf("main iVal (int):\t%p\n", &iVal);
+	printf("main iErr (int):\t%p\n", &iErr);
+
+	for(int i=0; i<MAXVALS; i++)
+		printf("\t%d", a[i]);
+	printf("\n");
+
+	return EXIT_SUCCESS;
+}
+
+void arrayVals(int iN, int* arr, int val)
+{
+	printf("arrayVals arr (int*):\t%p\n",&arr);
+	printf("arrayVals val (int):\t%p\n",&val);
+	printf("arrayVals iN (int):\t%p\n",&iN);
+	for(int i=0; i<iN; i++)
+		arr[i]= val;
+}
+
+/*
+value: 3
+arrayVals arr (int*):	0x7ffc99b277d0
+arrayVals val (int):	0x7ffc99b277d8
+arrayVals iN (int):		0x7ffc99b277dc
+-------------------------------------------
+main prompt (char*):	0x7ffc99b27808
+main a (int[MAXVALS]):	0x7ffc99b27810
+main iVal (int):		0x7ffc99b27824
+main iErr (int):		0x7ffc99b27828
+	3	3	3	3
+*/
+

Labs/Lab4/Lec10src/mallocfree.c

@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MAXVALS 4
+
+int main(void){
+
+	// allocate space for a float on the heap, 
+	// return a pointer to it, 
+	// cast it to a float* ,
+	// store it in f;
+	float* pf = (float*) malloc( sizeof(float) );
+	if(pf == (float*)NULL){ 
+		fprintf(stderr, "Memory allocation failed. Program terminating.");
+		return EXIT_FAILURE;
+	}
+	printf("Please enter a float value: ");
+	scanf("%f",pf); // pf is a pointer, with space allocated to it
+	printf("%f it is!\n", *pf);
+	free(pf); // all done with fp
+
+	// allocate space for an integer [] that hold MAXVALS ints on the heap,
+	// return a pointer to it, cast the void* to a int* , and store it in arr;
+	int iErr;
+	int* arr = (int*) malloc( sizeof(int)*MAXVALS );
+	if(arr == (int*)NULL){ 
+		fprintf(stderr, "Memory allocation failed. Program terminating.");
+		return EXIT_FAILURE;
+	}
+	printf("Please enter %d integer values: ", MAXVALS);
+	for(int i=0; i<MAXVALS; i++){
+		iErr = scanf("%d",&arr[i]); // arr is a pointer, with space allocated
+		if(iErr != 1){
+			fprintf(stderr, "Read failed. Program terminating.");
+			free(arr);
+			return EXIT_FAILURE;
+		}
+		printf("%d it is!\n", arr[i]);
+	}
+	free(arr); //all done with arr
+
+	// allocate space for an char [] of that hold MAXVALS chars on the heap 
+	// (with room for the NULL), return a pointer to it, cast it to a char* ,
+	// and store it in s. 
+	// Note that although s isn't YET a string, that's the intention.
+	char* s = (char*) malloc( sizeof(char)*(MAXVALS+1) );
+	if(pf == (float*)NULL){ 
+		fprintf(stderr, "Memory allocation failed. Program terminating.");
+		return EXIT_FAILURE;
+	}
+	printf("Enter up to four characters: ");
+	getchar(); // flushes newline feed from last response
+	char c = getchar();
+	int i = 0;
+	while(c != '\n' && i < MAXVALS){ // leave room for the terminating NULL!
+		s[i] = c;
+		i++;
+		c = getchar();
+	}
+	s[i] = (char) NULL; // terminate the string
+	printf("%s it is!\n", s);
+	free(s); // all done with s
+
+	return EXIT_SUCCESS;
+}
+
+

Labs/Lab4/Lec10src/stringTest.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "Strings.h"
+
+// copies the program name (argv[0]) to a new string, prints it out
+int main(int argc, char* argv[]){
+
+	char* programName;
+
+	programName = duplicateString(argv[0]);
+	if(programName == (char*)NULL){
+		fprintf(stderr,"Memory failure, terminating");
+		return EXIT_FAILURE;
+	}
+	// Did we do it? Can we print it out?
+		printf("%s\n", programName);
+
+	free(programName);
+
+	return EXIT_SUCCESS;
+}
+
+