我的最后一个printf语句未打印,我不确定是什么问题,因为我正在使用getchar读取标准输入,因此我也必须使用%s来解决此问题。我试图使最后一个printf语句从标准输入中打印出确切的输入。
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#define INITIAL_BUFFER_SIZE 16
// Input: pointer to the the old_Buffer i.e. *buffer and the pointer to the old_Buffer size i.e. *buffer_size
// Output: pointer to the new_Buffer i.e. *temp
// Summary: Function to increase the buffer size to double whenever the old_Buffer reaches the max possible size
char* IncreaseBuffer(char *buffer,int *buffer_size){
// Creating a new buffer of double the size
int temp_sz = *buffer_size;
temp_sz = 2*temp_sz;
char *temp;
temp = realloc(buffer, temp_sz);
// If the allocation is not successful, then exit the program and print the error
if (!temp) {
printf("Error: Unable to Realloc\n");
exit(EXIT_FAILURE);
}
// Update the buffer size as per the new buffer and return the new buffer instead of the old buffer
*buffer_size = temp_sz;
return temp;
}
int main(void){
// INITIAL BUFFER
char *myString;
myString = malloc(INITIAL_BUFFER_SIZE);
int curr_size = INITIAL_BUFFER_SIZE;
// TEMPORARY CHARACTER TO STORE THE READ CHARACTER
char ch;
printf("Enter a string: ");
// Number of buffer increases
int buff_inc = 0;
// Length of the string
int len = 0;
while((ch=getchar())!=EOF){
if(ch == '\n'){
// If character read is a new line, then we break and assume that we have got our string to print by now
break;
}else{
if(len >= curr_size - 1){
// If length of the string is greater than the buffer size, then we increase the buffer size
// Also increment the number of buffer increases
myString = IncreaseBuffer(myString, &curr_size);
buff_inc++;
}
// Append the read character to the end of the buffer
myString[len++] = ch;
}
}
printf("String size: %d\n", len);
printf("Buffer increases: %d\n", buff_inc);
printf("You entered: %s\n",myString);
return 0;
}
最佳答案
调用realloc
后,一定不能释放旧缓冲区。那很不好。它已经过调整大小,内存分配已处理完毕。重新分配后,它甚至可能保留相同的地址。
只需删除以下几行:
// Free the old buffer
free(buffer);
buffer = NULL;
并且,在注释中已经指出,您忘记了终止字符串。在循环之后执行此操作:
myString[len] = '\0';