一个读text文本文件和解析文本的例子（C语言）

一个读text文本文件和解析文本的例子。

（1）引入头文件

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

（2）函数int initConfigFile(const char * pFileName)

/**
* initConfigFile()
* return:
*   1 create file success
*   0 create file failed
*/
int initConfigFile(const char * pFileName)
{
int rval = 0;

FILE *pFile;
char buffer[1024] = {0};
int strLen = 0;
int bytes = 0;

if ((pFile = fopen(pFileName, "wb")) == NULL) {
printf("File cannot be created\n");
return rval;
}

sprintf(buffer, "GPRMC;204522/00;A;2233.94321;N;11402.42498;E");
strLen = strlen(buffer);
bytes = fwrite(buffer, 1, strLen, pFile);
if (bytes == strLen) {
printf("Initial Configuration File success!\n");
rval = 1;
}

fclose(pFile);
return rval;
}

（3）函数int parseConfigFile(const char * pFileName)

/**
* parseConfigFile()
* return:
*   1 parse file success
*   0 parse file failed
*/
int parseConfigFile(const char * pFileName)
{
int rval = 0;

FILE *pFile;
long file_size = 0;
char *buffer = NULL;
long bytes = 0;
long i = 0;
long numberCRLF = 0;

int semiNum = 0;	// Number of semicolon
int slashNum = 0;	// Number of slash

long strLen = 0;
char *array = NULL;
char *pos1 = NULL;
char *pos2 = NULL;

//////////////////////////////////////////////////////////////////////////
if ((pFile = fopen(pFileName, "rb")) == NULL) {
printf("File cannot be opened\n");
return rval;
}

fseek(pFile, 0, SEEK_END);
file_size = ftell(pFile);
rewind(pFile);
printf("file_size: %d\n", file_size);

buffer = (char*)malloc(sizeof(char) * (file_size + 1 + 1));	// +1 For strcat(buffer, ";"); later.
if (!buffer) {
printf("Insufficient memory available\n" );
fclose(pFile);
return rval;
}
memset(buffer, 0, (file_size + 1 + 1));	// +1 For strcat(buffer, ";"); later.

bytes = fread(buffer, sizeof(char), file_size, pFile);
printf("read char: %d\n", bytes);
buffer[file_size] = '\0';
if (file_size == bytes) {
printf("read:\n%s\n", buffer);
} else {
printf("read error\n");
fclose(pFile);
free(buffer);
return rval;
}

fclose(pFile);

//////////////////////////////////////////////////////////////////////////
// 1. Check the numbers of semicolon and slash
strLen = strlen(buffer);
for (i = 0; i < strLen; i ++) {
if (';' == buffer[i]) {
semiNum++;
} else if ('/' == buffer[i]) {
slashNum++;
}
}

printf("semicolon: %d, slash: %d\n", semiNum, slashNum);

if ((semiNum < 6) || (slashNum < 1))
{
printf("Configuration file invalid!\n");
rval = initConfigFile(pFileName);
return rval;
}

//////////////////////////////////////////////////////////////////////////
// 2. Delete CRLF, beginning of string
strLen = strlen(buffer);
array = (char *)malloc(sizeof(char) * (strLen + 1));
if (!buffer) {
printf("Insufficient memory available\n" );
fclose(pFile);
return rval;
}
memset(array, 0, (strLen + 1));
pos2 = buffer;
for (i = 0; i < strLen; i++) {
if (('\r' == buffer[i]) || ('\n' == buffer[i])) {
pos2++;
} else {
break;
}
}

strcpy(array, pos2);
strcpy(buffer, array);
printf("Delete CRLF, beginning of string:\n%s\n", buffer);

//////////////////////////////////////////////////////////////////////////
// 3. Delete CRLF, end of string
strLen = strlen(buffer);
free(array);
array = (char *)malloc(sizeof(char) * (strLen + 1));
if (!buffer) {
printf("Insufficient memory available\n" );
fclose(pFile);
return rval;
}
memset(array, 0, (strLen + 1));
numberCRLF = 0;
for (i = (strLen - 1); i >= 0; i--) {
if (('\r' != buffer[i]) && ('\n' != buffer[i])) {
break;
} else {
numberCRLF++;
}
}

strncpy(array, buffer, (strLen - numberCRLF));
strcpy(buffer, array);
printf("Delete CRLF, end of string:\n%s\n", buffer);

//////////////////////////////////////////////////////////////////////////
// 4. Remove spaces at the beginning of the string
strLen = strlen(buffer);
free(array);
array = (char *)malloc(sizeof(char) * (strLen + 1));
if (!buffer) {
printf("Insufficient memory available\n" );
fclose(pFile);
return rval;
}
memset(array, 0, (strLen + 1));
pos2 = buffer;
for (i = 0; i < strLen; i++) {
if (' ' == buffer[i]) {
pos2++;
} else {
break;
}
}

strcpy(array, pos2);
strcpy(buffer, array);
printf("Remove spaces at the beginning of the string:\n%s\n", buffer);

//////////////////////////////////////////////////////////////////////////
// 5. parse the string
strcat(buffer, ";");
strLen = strlen(buffer);
free(array);
array = (char *)malloc(sizeof(char) * (strLen + 1));
if (!buffer) {
printf("Insufficient memory available\n" );
fclose(pFile);
return rval;
}
memset(array, 0, (strLen + 1));
pos1 = NULL;
pos2 = buffer;
pos1 = strstr(pos2, ";");
while (NULL != pos1) {
strncpy(array, pos2, (pos1 - pos2));
array[(pos1 - pos2)] = '\0';
printf("array: %s\n", array);
pos2 = pos1 + 1;
pos1 = strstr(pos2, ";");
}

free(array);
free(buffer);

rval = 1;
return rval;
}

（4）main函数

int main(int argc, char *argv[])
{
int result =0;

result = parseConfigFile("config.ini");

if (result) {
printf("Parse File success!\n");
} else {
printf("Parse File failed!\n");
}

return 0;
}