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C语言获得文件大小时ftell始终返回-1
long GetFileLength(FILE* fileptr) { if (fileptr == NULL) return 0; /*fileptr=NULL是赋值语句，应为==*/ long fOffset = ftell(fileptr); if (fseek(fileptr, 0, SEEK_END)《0) return 0; /*fseek函数失败时返回负值*/ long file_size = ftell(fileptr); fseek(fileptr, fOffset, SEEK_SET); return file_size;}
来个大神帮我调试一下吧现在遇到的问题就是ftell怎么读文件长度都是-1，后续就不知道怎么办了
#include 《stdio.h》#include 《stdlib.h》 //最好加上这个头文件，里面有malloc和free函数int countKeyChar(char *buffer, char keyChar){int i;int cnt = 0;for(i=0; buffer != ’\0’; i++){if(buffer = keyChar){cnt++;}}return cnt;}FILE *openFile(char *fileName, char *openMethod){FILE *fp;if((fp = fopen(fileName, openMethod)) == NULL) //这边，用括号将fp = fopen括起来{printf("Cannot open file!\n");return 0;}return fp;}void closeFile(FILE *fp){if(fp == NULL){printf("No file!\n");return;}fclose(fp);}int getFileLength(FILE *fp){int len;fseek(fp, 0, SEEK_END); len = ftell(fp);printf("%d.......",len);return len;}char *readData(FILE *fp, int n){int i;char *buffer;buffer = (char *)malloc(sizeof(char) * n + 1);for(i=0; i《n; i++){buffer = fgetc(fp);}buffer = ’\0’;return buffer;}int main(){FILE *fp; char keyChar; char *buffer; char fileName;int fileLen; int cnt; printf("Input file name: ");scanf("%s", fileName);getchar(); printf("Input key character: ");scanf("%c", &keyChar);fp = openFile(fileName, "r");fileLen = getFileLength(fp); buffer = readData(fp, fileLen); cnt = countKeyChar(buffer, keyChar); printf("The number of \’%c\’: %d\n", keyChar, cnt);free(buffer); closeFile(fp);system("pause");return 0;}
你再试试，程序本身没什么问题，修改后的代码在vs2005中，可以获取文件大小
