char *myStrstr(char * first, char *second){
/*Compute the lengths of the strings*/
int lengthF = myStrlen(first);
int lengthS = myStrlen(second);
/*Compute the pattern vector for the second string*/
int *p = pattern(second);
/*f_index is an iterator for the first string
s_index is an iterator for the second string*/
int f_index = 0, s_index = 0;
/*Iterate the first string*/
while(f_index < lengthF){
/*If the current characters match,
advance to the next characters*/
if(second[s_index] == first[f_index])
{
f_index++;
s_index++;
}
/*A match of the string was found*/
if(s_index == lengthS){
free(p); /*Free the memory used for the pattern vector*/
/*Return a pointer to the match*/
return first + f_index - s_index;
}
/*If characters do not match anymore*/
else if(f_index < lengthF && second[s_index] != first[f_index]){
/*If we may still have a pattern*/
if(s_index)
/*Try a shorter prefix suffix*/
s_index = p[s_index - 1];
else
/*Go to the next character in the first string*/
f_index++;
}
}
/*Deallocate the memory for the pattern vector*/
free(p);
/*No pattern found means returning NULL*/
return NULL;
}
char* myStrmove( char * const dest, const char * const src )
{
if ( dest == src )
{
return dest;
}
if ( dest < src )
{
size_t index = 0;
while ( (dest[index] = src[index]) != '\0' )
{
++index;
}
}
else
{
for ( int i=(int)myStrlen(src); i>-1; --i )
{
dest[i] = src[i];
}
}
return dest;
}
char* myStrmove( char * const dest, const char * const src )
{
if( dest == src )
{
return dest;
}
else
{
size_t index = 0;
if( dest > src )
{
size_t srcLen = myStrlen( src );
for ( int i=(int)srcLen; i>-1; --i )
{
dest[i] = src[i];
}
}
else
{
while ( (dest[index] = src[index]) != '\0' )
{
++index;
}
}
}
return dest;
}
int main(){
char* source = "abc";
char* destination=malloc((strlen(source)+1)*sizeof(char));
destination=mystrcpy(destination,source);
printf("%d \n",myStrlen(destination));
printf("%s \n",myStrdup(source));
}
int main()
{
char temp[256];
printf("Please enter a sentence: ");
gets(temp);
printf("The sentence entered is %u characters long.\n",myStrlen(temp));
return 0;
}
void myStrlwr(char *str){
int stringSize = myStrlen(str);
for(int index = 0; index < stringSize; index++){
str[index] = myTolower( str[index] );
}
}
char *reverse(char *str)
{
int end = (int)myStrlen(str);
char *ret = malloc((unsigned long)end);
for (int i=0; str[i]; ++i)
{
ret[end-i-1] = str[i]; // Subtract 1 because ret[end] returns 0
}
return ret;
}
char* myStrcat( char * const dest, const char * const src )
{
size_t destLen = myStrlen( dest );
size_t index = 0;
while ( (dest[destLen+index] = src[index]) != '\0' )
{
++index;
}
return dest;
}
char *switchCases(char *str)
{
char *ret = malloc(myStrlen(str));
for (int i=0; str[i]; ++i)
{ // Excuse the clump below. I saw no reason in using curly braces when all I'm doing is one thing each.
if (islower(str[i])) ret[i]=(char)toupper(str[i]);
else if (isupper(str[i])) ret[i]=(char)tolower(str[i]);
else ret[i] = str[i];
}
return ret;
}
char *extracttoend(char *str, int start) // Used for myStrchr and myStrstr
{
unsigned long lenstr = myStrlen(str);
char *extract = (char *) malloc((lenstr-(unsigned long)start+1));
// Dynamically allocate memory that wouldn't be erased. Size of string should just fit.
int beg = start;
for (int i=0; i<((int)lenstr-start+1); ++i)
{
extract[i] = str[beg];
++beg;
}
return extract;
}
/**
* @brief Generates the message for the the ID of the system.
*
* @param[out] Cbuff Pointer to the circular buffer to put the data in.
* @return HAL_FAILED if the message didn't fit or HAL_SUCCESS
* if it did fit.
*/
static bool GenerateGetDeviceInfo(circular_buffer_t *Cbuff)
{
const uint32_t size = 6;
uint8_t header[2];
uint8_t *ptr_list[size];
uint32_t len_list[size];
uint32_t data_count, i;
uint16_t crc16;
/* The strings are at known locations. */
ptr_list[0] = header;
ptr_list[1] = (uint8_t *)ptrGetUniqueID();
ptr_list[2] = (uint8_t *)ptrGetBootloaderVersion();
ptr_list[3] = (uint8_t *)ptrGetFirmwareVersion();
ptr_list[4] = ptrGetUserIDString();
ptr_list[5] = (uint8_t *)&crc16;
/* Find the length of the strings, + 1 for the null byte. */
len_list[0] = 2;
len_list[1] = UNIQUE_ID_SIZE;
len_list[2] = myStrlen(ptr_list[2], VERSION_MAX_SIZE) + 1;
len_list[3] = myStrlen(ptr_list[3], VERSION_MAX_SIZE) + 1;
len_list[4] = myStrlen(ptr_list[4], USER_ID_MAX_SIZE) + 1;
len_list[5] = 2;
/* Calculate data size. */
data_count = UNIQUE_ID_SIZE + len_list[2] + len_list[3] + len_list[4] ;
/* Fill header and build the CRC. */
header[0] = Cmd_GetDeviceInfo;
header[1] = (uint8_t) data_count;
crc16 = CRC16_START_VALUE;
for (i = 0; i < size - 1; i++)
crc16 = CRC16_chunk(ptr_list[i], len_list[i], crc16);
return GenerateSLIP_MultiChunk(ptr_list, len_list, size, Cbuff);
}
int _tmain(int argc, _TCHAR* argv[])
{
int c[10] = { 1,2,3,4,5,6,7,8,9,10 };
int d[10];
myMemcpy( d, c, sizeof( int )*10 );
outputArray( c, 10 );
outputArray( d, 10 );
printf( "%d\n", myMemcmp( c, d, sizeof( int )*10 ) );
myMemmove( c, &c[2], sizeof( int )*8 );
outputArray( c, 10 );
myMemmove( &c[2], c, sizeof( int )*8 );
outputArray( c, 10 );
myMemset( d, 0, sizeof( int )*10 );
outputArray( d, 10 );
char a[100] = "123456789";
char b[100] = "abcdefghijklmn";
printf( "%d\n", myStrlen( a ) );
printf( "%d\n", myStrlen( b ) );
printf( "%s\n", myStrcat( b, a ) );
//printf( "%s\n", myStrcat( a, &a[2] ) );
//printf( "%s\n", myStrcat( &a[2], a ) );
printf( "%s\n", a );
printf( "%d\n", myStrcmp( b, a ) );
printf( "%s\n", myStrcpy( b, a ) );
printf( "%s\n", myStrmove( a, &a[3] ) );
printf( "%s\n", myStrmove( &a[4], a ) );
printf( "%s\n", a );
return 0;
}
char *replaceDigits(char *str, int c)
{
char *ret = malloc(myStrlen(str));
for (int i=0; str[i]; ++i)
{
if (isdigit(str[i]))
{
ret[i] = (char)c;
continue;
}
ret[i] = str[i];
}
return ret;
}
char *removeSpaces(char *str)
{
char *ret = malloc(myStrlen(str)); // This will likely not completely fill up
int spaces = 0; // Keep track of spaces so chars placed in ret would be in the right position
for (int i=0; str[i]; ++i)
{
if (isspace(str[i]))
{
++spaces;
continue;
}
ret[i-spaces] = str[i];
}
return ret;
}
char *removeVowels(char *str)
{
int count = 0; // Same concept used in removeSpaces
char *ret = malloc(myStrlen(str));
for (int i=0; str[i]; ++i)
{
if (isvowel(str[i]))
{
++count;
continue;
}
ret[i-count] = str[i];
}
return ret;
}
void tests()
{
char a[] = {"String."};
printf("%d\n", myStrlen(a));
char b[20] = {0};
myStrcpy(b, a);
printf("%s\n", b);
char c[20] = {0};
myStrcpy(c, a);
myStrcat(c, b);
printf("%s\n", c);
printf("%d\n", myStrcmp(a, b));
printf("%d\n", myStrcmp(b, c));
}
void myStrrev(char *str){
char *strEnd = str + myStrlen(str) - 1;
char auxCharacter;
while(str < strEnd){
auxCharacter = *str;
*str = *strEnd;
*strEnd = auxCharacter;
str++;
strEnd--;
}
}
/*Creates the pattern of a string
The pattern will be used only by the myStrstr() function
As a result, the user of the library
will not have access to this function*/
int *pattern(char *str){
/*Length of the string*/
int n = myStrlen(str);
/*Allocate memory for the pattern vector*/
int *p = malloc(n * sizeof(int));
p[0] = 0;
int index = 1, currentLen = 0;
/*Iterate from 1 to n-1*/
while(index < n){
/*If characters match*/
if(str[currentLen] == str[index]){
/*Set the length of the current prefix suffix*/
currentLen++;
p[index] = currentLen;
index++;
}
else{
/*Try to find a suffix of the current prefix with
a smaller length*/
if(currentLen != 0){
currentLen = p[currentLen - 1];
}
/*All the suffixes of the current prefix were tried
and no match found*/
else{
p[index] = 0;
index++;
}
}
}
/*Return the pattern vector*/
return p;
}
char* myStrtok(char *str, char *delimiters){
static char *current, *next, *endStr;
/*Check if this is the first call for a string*/
if(str != NULL){
/*If so, compute the pointer to the position of
the '\0' character (string terminator) -> endPosition*/
endStr = str + myStrlen(str);
/*Set the next pointer to be returned and the
to be the beginning of the string*/
next = str;
/*Skip the charactern in the beginning of the string
which are delimiters*/
while(next < endStr && myStrchr(delimiters, *next))
next++;
/*If the end of the string was reached return NULL*/
if(next == endStr)
return NULL;
current = next;
}
else{
/*Return the NULL pointer if the string cannot be split anymore*/
if(current == endStr){
return NULL;
}
/*Get the next part of the string*/
current++;
/*Save the pointer to it to next*/
next = current;
}
/*While the end of the string hasn't been reached and a delimiter
hasn't been found keep iterating*/
while(*current){
/*If the current substring is valid (starts with a non-delimiter, ends
right before a delimiter)
Stop iterating*/
if(!myStrchr(delimiters, *next) && myStrchr(delimiters, *current))
break;
/*If next points to a delimiter,
skip to the following character*/
if(myStrchr(delimiters, *next)){
next = current;
}
current++;
}
/*Make the character at the current position a string terminator*/
*current = '\0';
/*Return the pointer to the next part of the string*/
/*CORNER CASE: current reached the end of the string, but
the character to which next is pointing is a delimiter
CORNER CASE: next reaches the string terminator*/
return myStrchr(delimiters, *next) || *next == '\0'? NULL : next;
}
int main() {
printf("String length of pie = %d\n", myStrlen("pie"));
return 0;
}
