这不是一个问题。这是未来观看者的解决方案。
我提供了读取 CSV 浮动的代码。 如果有人需要用谷歌搜索，这可能会有所帮助。
不过，由于我只是一名本科生，这段代码可能在安全性和内存泄漏方面并不完美。如果通过使用缓存优化不需要过多使用指针，它也可以具有更高的性能。
但是，它确实有效，而且总比没有好，
如果您想重构此代码或解释如何做得更好（为了最大限度地利用 stackoverflow 的能力，请随意这样做）
数据.csv
0.1,0.2,0.3,0.4,0.5
1.1,1.2,1.3,1.4,1.5
2.1,2.2,2.3,2.4,2.5
3.1,3.2,3.3,3.3,3.5
4.1,4.2,4.3,4.4,4.5
输出：
------------START OF PROGRAM------------
Filesize: 99 Bytes
CSV_content =
[ 0.100000 0.200000 0.300000 0.400000 0.500000 ]
[ 1.100000 1.200000 1.300000 1.400000 1.500000 ]
[ 2.100000 2.200000 2.300000 2.400000 2.500000 ]
[ 3.100000 3.200000 3.300000 3.300000 3.500000 ]
[ 4.100000 4.200000 4.300000 4.400000 4.500000 ]
------------END OF PROGRAM------------
旧答案：
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
const unsigned long MAX_NUMBER_OF_LINE = 128;
const int MAX_LENGTH_OF_STRING_ELEMENT = 16;
const char NULL_TERMINATOR = '\0';
const char NEW_LINE_CHARARACTER = '\n';
typedef struct
{
int numberOfString; // number of string
char **data; // stringArray->data[i] is a string.
} StringArray;
typedef struct
{
char ***data;
int numberOfStringArray;
int numberOfString; // number of string
} StringMatrix;
char *readCSV_toString(char *filename, int printFileBool, unsigned long *fileSize_output)
{
FILE *filePointer = fopen(filename, "rb");
if (filePointer == NULL)
{
printf("Can't Open File");
return NULL;
}
fseek(filePointer, 0L, SEEK_END);
unsigned long fileSize = ftell(filePointer); // get length of file
rewind(filePointer); // return to beginning of file
char *fileContent = (char *)malloc(sizeof(char) * (fileSize) + 1);
fread(fileContent, sizeof(char), fileSize / sizeof(char), filePointer);
fileContent[fileSize] = NULL_TERMINATOR; // add nullterminator
if (printFileBool == 1)
{
for (int i = 0; i < fileSize + 1; i++)
{
printf("%i ", fileContent[i]);
}
}
fclose(filePointer);
*fileSize_output = fileSize;
return fileContent;
}
int splitLength(char *string, unsigned long stringSize, char *delimiter)
// return the number of element in arrayList that the initial string will be split into
{
int length = 0;
for (unsigned long i = 0; i < stringSize + 1; i++)
{
if (string[i] == delimiter[0] && (string[i + 1] != NULL_TERMINATOR))
{
length++;
}
}
return length + 1; // because there (a,b,c,d): 3 commas, 4 number. Hence +1
}
StringArray *splitString(char *string, char *delimiter, int maxElementSize)
// return the string.split(delimiter)
{
StringArray *stringArray = calloc(1, sizeof(StringArray)); // the big thing
stringArray->numberOfString = splitLength(string, maxElementSize, delimiter);
int i = 0;
char *token = strtok(string, delimiter);
char *stringOutput_i = (char *)malloc(maxElementSize); // malloc str[i] : Important
strncpy(stringOutput_i, token, maxElementSize);
stringArray->data = calloc(stringArray->numberOfString, sizeof(char *)); // The array of pointers. (inside of the big thing. )
stringArray->data[i] = stringOutput_i;
i++;
// free(token);
while (token != NULL && i < MAX_NUMBER_OF_LINE)
{
token = strtok(NULL, delimiter);
if (token == NULL)
break; // needed because it loop 1 too many time.
char *stringOutput_i = (char *)malloc(maxElementSize); // malloc str[i] : Important
strncpy(stringOutput_i, token, maxElementSize);
stringArray->data[i] = stringOutput_i; // pointer copy.
i++;
// free(token); //Do not free(token), it's not supposed to be free. Its a dumb pointer for data[i][j] or data[i];
}
return stringArray;
}
void printStringArray(StringArray stringArray)
{
printf("[ ");
int iLast = stringArray.numberOfString - 1;
for (int i = 0; i < stringArray.numberOfString; i++)
{
printf("'%s'", stringArray.data[i]);
if (i != iLast)
printf(",");
printf(" ");
}
printf("]\n");
}
StringMatrix *getStringMatrix(StringArray *stringArray_input, char *delimiterElement, int maxElementSize)
{
StringMatrix *stringMatrix = calloc(1, sizeof(StringMatrix));
stringMatrix->numberOfStringArray = stringArray_input->numberOfString;
char buffer[maxElementSize];
strncpy(buffer, stringArray_input->data[0], maxElementSize);
StringArray *initArray = splitString(buffer, delimiterElement, maxElementSize);
stringMatrix->numberOfString = initArray->numberOfString;
stringMatrix->data = malloc(stringMatrix->numberOfStringArray * sizeof(char **));
for (int i = 0; i < stringMatrix->numberOfStringArray; i++)
{
stringMatrix->data[i] = malloc(stringMatrix->numberOfString * sizeof(char *));
}
for (int i = 0; i < stringMatrix->numberOfStringArray; i++)
{
StringArray *elementArray = splitString(stringArray_input->data[i], ",", 100);
for (int j = 0; j < stringMatrix->numberOfString; j++)
{
stringMatrix->data[i][j] = (elementArray->data[j]); // pointer copy
}
}
return stringMatrix;
}
float *stringToFloat_matrix(StringMatrix *stringMatrix, int *m_output, int *n_output)
{
int n = stringMatrix->numberOfStringArray; // vertical (list of list)
int m = stringMatrix->numberOfString; // horizontal (last layer)
float *array1D = calloc(m * n, sizeof(float));
float(*matrix)[m] = (float(*)[m])array1D;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
matrix[i][j] = (float)atof(stringMatrix->data[i][j]);
}
}
*m_output = m;
*n_output = n;
return array1D;
}
void freeStringArray(StringArray *stringArray)
{
for (int i = 0; i < stringArray->numberOfString; i++)
{
free(stringArray->data[i]);
}
free(stringArray->data); // stringArray (-> numberOfString , -> data -> [ p0, p1, p2, p3,... ] -> { string1, string2, string3,... } )
free(stringArray);
}
void freeStringMatrix(StringMatrix *stringMatrix)
{
for (int i = 0; i < stringMatrix->numberOfStringArray; i++)
{
for (int j = 0; j < stringMatrix->numberOfString; j++)
{
free(stringMatrix->data[i][j]);
}
free(stringMatrix->data[i]);
}
free(stringMatrix->data);
free(stringMatrix);
}
float *openCSV_float(char *filename, char *delimiterLine, char *delimiterElement, int printFileContentBool, int *m_output, int *n_output)
{
unsigned long fileSize;
char *fileContent = readCSV_toString(filename, printFileContentBool, &fileSize);
printf("Filesize: %lu Bytes\n\n", fileSize);
StringArray *stringArray = splitString(fileContent, delimiterLine, MAX_NUMBER_OF_LINE);
StringMatrix *stringMatrix = getStringMatrix(stringArray, delimiterElement, MAX_LENGTH_OF_STRING_ELEMENT);
int m, n;
float *array1D = stringToFloat_matrix(stringMatrix, &m, &n);
*m_output = m;
*n_output = n;
// Could have put m_output, n_output in stringToFloat_matrix. And would save on 3 line of code and a bit more performance
// But decided to be verbose.
free(fileContent);
freeStringArray(stringArray);
freeStringMatrix(stringMatrix);
// other stuff to free? idk. Should be the main leak solved.
return array1D;
}
void printMatrix_float(float *array1D, int m, int n)
{
float(*matrix)[m] = (float(*)[m])array1D;
for (int i = 0; i < n; i++)
{
printf("[ ");
for (int j = 0; j < m; j++)
{
printf("%f ", matrix[i][j]);
}
printf("]\n");
}
}
void useFloatMatrix();
void main()
{
printf("\n\n------------START OF PROGRAM------------\n");
int n, m;
int printFileContentBool = 0;
float *array1D;
char delimiterLine[2] = {NEW_LINE_CHARARACTER, NULL_TERMINATOR};
char delimiterElement[3] = ","; //extra byte of space to show it can work
char filename[100] = "data.csv";
array1D = openCSV_float(filename, delimiterLine, delimiterElement, printFileContentBool, &m, &n);
// 1kb of memory leak per file opening loop;
printf("CSV_content =\n");
printMatrix_float(array1D, m, n);
printf("\n------------END OF PROGRAM------------");
}
typedef struct
{
int m;
int n;
float data[];
} FloatMatrix; // Could use it but I don't end up using it.
void useFloatMatrix(int m, int n)
{
FloatMatrix *mat = alloca(sizeof(int) * 2 + m * n * sizeof(float));
// alloca: allocate on stack. freed at end of function (when $sp_current > $sp_created {stack goes down} )
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
((float(*)[m])(mat->data))[i][j] = 10 * (i + 1) + j; // does it still do 2 pointer derefence?
}
}
float(*matrixGoodType)[m] = ((float(*)[m])(mat->data));
printf("\nDoing tests inside use float matrix \n");
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
printf("%f ", matrixGoodType[i][j]);
}
printf("\n");
}
// all data from mat is on the stack. It should be consecutive in location;
}
更好的代码：
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
const int MAX_NUMBER_OF_LINE = 128;
const int MAX_LINE_SIZE = 256;
const int MAX_LENGTH_OF_STRING_ELEMENT = 11; // for floats. Increase for double 0.1234567\0 = 10 character.
const char NULL_TERMINATOR = '\0';
const char NEW_LINE_CHARARACTER = '\n';
typedef struct
{
int numberOfString; // number of string
char **data; // stringArray->data[i] is a string.
} StringArray;
typedef struct
{
char ***data;
int numberOfStringArray;
int numberOfString; // number of string
} StringMatrix;
char *readCSV_toString(char *filename, int printFileBool, unsigned long *fileSize_output)
{
FILE *filePointer = fopen(filename, "rb");
if (filePointer == NULL)
{
fprintf(stderr, "%s","Can't open file '");
fprintf(stderr,"%s",filename);
fprintf(stderr,"%s","'\n");
return NULL;
}
fseek(filePointer, 0L, SEEK_END);
unsigned long fileSize = ftell(filePointer); // get length of file
rewind(filePointer); // return to beginning of file
char *fileContent = (char *)malloc(sizeof(char) * (fileSize) + 1);
if (fileContent == NULL)
{
fprintf(stderr, "Can't allocate memory for file %s\n");
return NULL;
}
fread(fileContent, sizeof(char), fileSize / sizeof(char), filePointer);
fileContent[fileSize] = NULL_TERMINATOR; // add nullterminator
if (printFileBool == 1)
{
for (int i = 0; i < fileSize + 1; i++)
{
printf("%i ", fileContent[i]);
}
}
fclose(filePointer);
*fileSize_output = fileSize;
return fileContent;
}
int substringCompare(char *stringInput, int start_index, int end_index_excluded, char *stringToBeCompared)
{
char *stringInputCut = (char *)malloc(sizeof(char) * (end_index_excluded - start_index) + 1);
for (int i = 0; i < end_index_excluded - start_index; i++)
{
stringInputCut[i] = stringInput[i + start_index];
}
// printf("max i (included):%d \n",end_index_excluded - 1);
stringInputCut[end_index_excluded - start_index] = NULL_TERMINATOR;
// printf("substring cut: '%s'\n", stringInputCut);
int return_value = strcmp(stringInputCut, stringToBeCompared);
free(stringInputCut);
return return_value;
}
int string_splitLength(char *string, unsigned long stringSize, char *delimiter)
// return the number of element in arrayList that the initial string will be split into
{
int length = 0;
int delimiterLength = strlen(delimiter);
// printf("string size :%d\n",stringSize);
for (unsigned long i = 0; i < stringSize - delimiterLength + 1; i++)
{
if (substringCompare(string, i, i + delimiterLength, delimiter) == 0 && (string[i + delimiterLength] != NULL_TERMINATOR))
{
// printf("___The substring is: %c%c___\n", string[i], string[i + 1]);
length++;
}
}
return length + 1; // because there (a,b,c,d): 3 commas, 4 number. Hence +1
}
StringArray *string_split(char *string, char *delimiter, int maxElementSize)
// return the string.split(delimiter)
{
StringArray *stringArray = calloc(1, sizeof(StringArray)); // the big thing
stringArray->numberOfString = string_splitLength(string, maxElementSize, delimiter);
int i = 0;
char *token = strtok(string, delimiter);
char *stringOutput_i = (char *)malloc(maxElementSize); // malloc str[i] : Important
strncpy(stringOutput_i, token, maxElementSize);
stringArray->data = calloc(stringArray->numberOfString, sizeof(char *)); // The array of pointers. (inside of the big thing. )
stringArray->data[i] = stringOutput_i;
i++;
while (token != NULL && i < MAX_NUMBER_OF_LINE)
{
token = strtok(NULL, delimiter);
if (token == NULL)
break; // needed because it loop 1 too many time.
char *stringOutput_i = (char *)malloc(maxElementSize); // malloc str[i] : Important
strncpy(stringOutput_i, token, maxElementSize);
stringArray->data[i] = stringOutput_i; // pointer copy.
i++;
}
return stringArray;
}
void printStringArray(StringArray *stringArray)
{
int n = stringArray->numberOfString;
printf("The string array with length %d is: \n", n);
printf("[ ");
for (int i = 0; i < stringArray->numberOfString; i++)
{
printf("'%s'", stringArray->data[i]);
if (i < n - 1)
printf(",");
printf(" ");
}
printf("]\n");
}
StringMatrix *getStringMatrix(StringArray *stringArray_input, char *delimiterElement, int maxElementSize)
{
StringMatrix *stringMatrix = calloc(1, sizeof(StringMatrix));
stringMatrix->numberOfStringArray = stringArray_input->numberOfString;
char buffer[MAX_LINE_SIZE];
strncpy(buffer, stringArray_input->data[0], MAX_LINE_SIZE);
StringArray *initArray = string_split(buffer, delimiterElement, MAX_LINE_SIZE);
stringMatrix->numberOfString = initArray->numberOfString;
stringMatrix->data = malloc(stringMatrix->numberOfStringArray * sizeof(char **));
for (int i = 0; i < stringMatrix->numberOfStringArray; i++)
{
stringMatrix->data[i] = malloc(stringMatrix->numberOfString * sizeof(char *));
}
for (int i = 0; i < stringMatrix->numberOfStringArray; i++)
{
StringArray *elementArray = string_split(stringArray_input->data[i], delimiterElement, MAX_LINE_SIZE);
for (int j = 0; j < stringMatrix->numberOfString; j++)
{
stringMatrix->data[i][j] = (elementArray->data[j]); // pointer copy
}
}
return stringMatrix;
}
void printStringMatrix(StringMatrix *stringMatrix)
{
int m = stringMatrix->numberOfString;
int n = stringMatrix->numberOfStringArray;
printf("The string matrix is: %d %d\n", m, n);
for (int i = 0; i < n; i++)
{
printf("[ ");
for (int j = 0; j < m; j++)
{
printf("'%s' ", stringMatrix->data[i][j]);
}
printf("]\n");
}
printf("\n");
}
float *stringToFloat_matrix(StringMatrix *stringMatrix, int *m_output, int *n_output)
{
int n = stringMatrix->numberOfStringArray; // vertical (list of list)
int m = stringMatrix->numberOfString; // horizontal (last layer)
float *array1D = calloc(m * n, sizeof(float));
float(*matrix)[m] = (float(*)[m])array1D;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
matrix[i][j] = (float)atof(stringMatrix->data[i][j]);
}
}
*m_output = m;
*n_output = n;
return array1D;
}
void freeStringArray(StringArray *stringArray)
{
for (int i = 0; i < stringArray->numberOfString; i++)
{
free(stringArray->data[i]);
}
free(stringArray->data); // stringArray (-> numberOfString , -> data -> [ p0, p1, p2, p3,... ] -> { string1, string2, string3,... } )
free(stringArray);
}
void freeStringMatrix(StringMatrix *stringMatrix)
{
for (int i = 0; i < stringMatrix->numberOfStringArray; i++)
{
for (int j = 0; j < stringMatrix->numberOfString; j++)
{
free(stringMatrix->data[i][j]);
}
free(stringMatrix->data[i]);
}
free(stringMatrix->data);
free(stringMatrix);
}
float *openCSV_float(char *filename, char *delimiterLine, char *delimiterElement, int printFileContentBool, int *m_output, int *n_output)
{
unsigned long fileSize;
char *fileContent = readCSV_toString(filename, printFileContentBool, &fileSize);
if (fileContent == NULL)
exit(1);
printf("Filesize: %lu Bytes\n\n", fileSize);
StringArray *stringArray = string_split(fileContent, delimiterLine, MAX_LINE_SIZE);
printStringArray(stringArray);
printf("-------\n");
StringMatrix *stringMatrix = getStringMatrix(stringArray, delimiterElement, MAX_LENGTH_OF_STRING_ELEMENT);
printStringMatrix(stringMatrix);
int m, n;
float *array1D = stringToFloat_matrix(stringMatrix, &m, &n);
*m_output = m;
*n_output = n;
// Could have put m_output, n_output in stringToFloat_matrix. And would save on 3 line of code and a bit more performance
// But decided to be verbose.
free(fileContent);
freeStringArray(stringArray);
freeStringMatrix(stringMatrix);
// other stuff to free? idk. Should be the main leak solved.
return array1D;
}
void printMatrix_float(float *array1D, int m, int n)
{
float(*matrix)[m] = (float(*)[m])array1D;
for (int i = 0; i < n; i++)
{
printf("[ ");
for (int j = 0; j < m; j++)
{
printf("%f ", matrix[i][j]);
}
printf("]\n");
}
}
int main()
{
printf("\n\n------------START OF PROGRAM------------\n");
int n, m;
int printFileContentBool = 0;
float *array1D;
char delimiterLine[2] = {NEW_LINE_CHARARACTER, NULL_TERMINATOR};
char delimiterElement[] = "||";
char filename[100] = "data2.csv";
array1D = openCSV_float(filename, delimiterLine, delimiterElement, printFileContentBool, &m, &n);
// 1kb of memory leak per file opening loop;
printf("CSV_content =\n");
printMatrix_float(array1D, m, n);
printf("\n------------END OF PROGRAM------------");
return 0;
}
数据.csv
0.1||0.2||0.3||0.4||0.5
1.1||1.2||1.3||1.4||1.5
2.1||2.2||2.3||2.4||2.5
3.1||3.2||3.3||3.3||3.5
输出
------------START OF PROGRAM------------
Filesize: 95 Bytes
The string array with length 4 is:
[ '0.1||0.2||0.3||0.4||0.5', '1.1||1.2||1.3||1.4||1.5', '2.1||2.2||2.3||2.4||2.5', '3.1||3.2||3.3||3.3||3.5' ]
-------
The string matrix is: 5 4
[ '0.1' '0.2' '0.3' '0.4' '0.5' ]
[ '1.1' '1.2' '1.3' '1.4' '1.5' ]
[ '2.1' '2.2' '2.3' '2.4' '2.5' ]
[ '3.1' '3.2' '3.3' '3.3' '3.5' ]
CSV_content =
[ 0.100000 0.200000 0.300000 0.400000 0.500000 ]
[ 1.100000 1.200000 1.300000 1.400000 1.500000 ]
[ 2.100000 2.200000 2.300000 2.400000 2.500000 ]
[ 3.100000 3.200000 3.300000 3.300000 3.500000 ]
------------END OF PROGRAM------------