该程序应该将现有的txt文件复制到新的txt代码文件中。然而,是不是正常工作。由于某种原因,它总是在第三次迭代后停止。 建议?
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void) {
char fileNameIn[100];
char fileNameOut[100];
FILE *ptrIn = NULL; //____ File Pointers
FILE *ptrOut = NULL;
char str[1000]; //this is used at fgets and it obtains sentences
/*_________________Counter variables)*/
char *token;
int ctr = 0;
int ndel = -1;
char wordA[10];
char sentence[101];
char del[10] = " !-,.";
;
int temp = 0;
printf("Enter the input filename: \n");
// gets(fileNameIn);
scanf("%s", fileNameIn);
//printf("You entered: %s\n",fileNameIn);
printf("Enter the output filename: \n");
scanf("%s", fileNameOut);
ptrIn = fopen(fileNameIn, "r"); // r is to read
ptrOut = fopen(fileNameOut, "w"); //w is to write on file
if (ptrIn == NULL || ptrOut == NULL) {
printf("Unable to open file\n");
exit(1);
}
//while(fgets (str,sizeof(str), ptrIn) )
while (fgets(str, sizeof(str), ptrIn)) { // while we are not at the end of the file
puts(str);
// if(temp==0)
// {
token = strtok(str, del);
temp = -1;
printf(
"Enter position of word to delete (Start counting at 0). Enter -1 to skip deletion:\n");
scanf("%d", &ndel);
printf("You selected: %d\n", ndel);
while (token != NULL) // while loop inside a sentence
{
if (ctr != ndel) {
strcpy(wordA, token);
}
token = strtok(NULL, del);
if (ctr != ndel) {
strcat(sentence, wordA);
strcat(sentence, " ");
printf("halfway?");
}
ctr++;
} // endof sentence loop
fprintf(ptrOut, "%s", sentence);
printf("the sentence is now:\n%s", sentence);
printf("___________________________________________");
printf("\n");
strcpy(sentence, "");
ctr = 0;
ndel = -1;
} //end of while loop eof
printf("Finish the main: ");
fflush(ptrOut);
fclose(ptrIn);
fclose(ptrOut);
return EXIT_SUCCESS;
}
这是现有文件的示例:
的test.txt:
hello my name is john.
this is a test.
after the third line the while
loop stops
this does the get copied
答案 0 :(得分:2)
您strcat()
到senetence
无法初始化它,strcat()
将搜索其第一个参数的终止nul
字节并开始从中复制字符&# 39;第二个参数从那个位置开始,所以很简单
sentence[0] = '\0';
在外部while
循环之后立即修复它,但是您的代码需要重新格式化,并且您应该通过检查每个潜在的未定义行为原因来使其更安全。
这是代码,现在可以正常使用
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
char fileNameIn[100] = {0};
char fileNameOut[100] = {0};
FILE *ptrIn = NULL;
FILE *ptrOut = NULL;
char str[1024] = {0};
char *token = NULL;
int ctr = 0;
int ndel = -1;
char wordA[1024] = {0};
char sentence[1024] = {0};
char del[] = " !-,.";
int temp = 0;
printf("Enter the input filename > ");
fflush(stdout);
scanf("%99s", fileNameIn);
printf("Enter the output filename > ");
fflush(stdout);
scanf("%99s", fileNameOut);
ptrIn = fopen(fileNameIn, "r"); // r is to read
if (ptrIn == NULL)
{
printf("Unable to open file %s\n", fileNameIn);
return -1;
}
ptrOut = fopen(fileNameOut, "w"); // w is to write on file
if (ptrOut == NULL)
{
fclose(ptrIn);
printf("Unable to open file %s\n", fileNameOut);
return -1;
}
while (fgets(str, sizeof(str), ptrIn)) // while we are not at the end of the file
{
puts(str);
token = strtok(str, del);
temp = -1;
printf("Enter position of word to delete (Start counting at 0) `-1 to skip deletion' > ");
if (scanf("%d", &ndel) != 1)
continue;
printf("You selected: %d\n", ndel);
sentence[0] = '\0';
while (token != NULL)
{
if (ctr != ndel)
strcpy(wordA, token);
token = strtok(NULL, del);
if (ctr != ndel)
{
strcat(sentence, wordA);
strcat(sentence, " ");
}
ctr++;
}
fprintf(ptrOut, "%s", sentence);
printf("the sentence is now:\n%s", sentence);
printf("\n");
ctr = 0;
ndel = -1;
}
printf("Finish the main: ");
fflush(ptrOut);
fclose(ptrIn);
fclose(ptrOut);
return EXIT_SUCCESS;
}