Question

正在创建我的2d数组char **缓冲区。 malloc部分有效。 realloc部分正在生成分段错误。

以下是执行以下操作的2个功能;

//sets up the array initially
void setBuffer(){
buffer = (char**)malloc(sizeof(char*)*buf_x);

for(int x=0;x<buf_x;x++){
    buffer[x] = (char *)malloc(sizeof(char)*buf_y);
}

if(buffer==NULL){
    perror("\nError: Failed to allocate memory");
}
}

//changes size
//variable buf_x has been modified
void adjustBuffer(){
for(int x=prev_x; x<buf_x;x++) {
    buffer[x] = NULL;
}

buffer=(char**)realloc(buffer,sizeof(char*)*buf_x);

for(int x=0; x<buf_x;x++){
    buffer[x]  = (char*)realloc(buffer[x],sizeof(char)*buf_y);
    strcpy(buffer[x],output_buffer[x]);
}
if(buffer == NULL){
    perror("\nError: Failed to adjust memory");
}
}

Answer 1

我猜buf_x是全球性的您需要存储原始大小并将其传递给该功能如果添加了元素，则需要将新元素设置为NULL，以便realloc成功。

//variable buf_x has been modified
void adjustBuffer( int original){
    buffer=realloc(buffer,sizeof(char*)*buf_x);
    for(int x=original; x<buf_x;x++){
        buffer[x] = NULL;//set new pointers to NULL
    }
    for(int x=0; x<buf_x;x++){
        buffer[x]  = realloc(buffer[x],sizeof(char)*buf_y);
    }
}

检查realloc是否失败

//variable buf_x has been modified
void adjustBuffer( int original){
    if ( ( buffer = realloc ( buffer, sizeof(char*) * buf_x)) != NULL) {
        for ( int x = original; x < buf_x; x++) {
            buffer[x] = NULL;//set new pointers to NULL
        }
        for ( int x = 0; x < buf_x; x++){
            if ( ( buffer[x] = realloc ( buffer[x], strlen ( output_buffer[x]) + 1)) == NULL) {
                break;
            }
            strcpy(buffer[x],output_buffer[x]);
        }
    }
}

重新分配**数组

1 个答案: