这段代码按照预期工作,但它从来没有释放malloc()
分配的内存。
我尝试在任何可以的地方释放内存,但无论我在哪里这样做,程序都会崩溃。具体地说,我会得到一个“double free or corruption”错误。这更多地是关于free()
和malloc()
实际上是做什么的问题?所有与释放有关的问题都在主要部分中:
int main(int argc, char *argv[]){
if(argc!=2){
exit(1);
}
printf("CSA WC version 1.0\n\n");
int length = strlen(argv[argc-1]);
char file_to_open[length];
strcpy(file_to_open, argv[argc-1]);
//printf("filename:%s\n",file_to_open);
//create counters for output
int count_number_of_lines = 0;
int count_number_of_words = 0;
int count_number_of_characters = 0;
//create int size of default array size
int current_array_size = pre_read(file_to_open);
//printf("number of lines: %i\n",current_array_size);
//create string array of default size
char *strings_array[current_array_size];
//create a pointer to catch incoming strings
char *incoming_string=NULL;
int done=0;
while(done==0){
incoming_string=get_line_from_file(file_to_open, count_number_of_lines);
if(incoming_string!=NULL){
incoming_string=csestrcpy2(incoming_string);
//printf("incoming line: %s\n",incoming_string);
strings_array[count_number_of_lines]=(char*)malloc(strlen(incoming_string+1));
strings_array[count_number_of_lines]=csestrcpy2(incoming_string);
//printf("added to array:%s\n",strings_array[count_number_of_lines]);
count_number_of_lines++;
count_number_of_characters=(count_number_of_characters+(strlen(incoming_string)-1));
}
else{
done=1;
}
}
//all data is stored in a properly sized array
//count all words in array
int count=0;
int word_count=0;
char *readline;
while(count<current_array_size){
readline = csestrcpy2(strings_array[count]);
printf("line being checked: %s", readline);
int i=0;
int j=1;
while( j< strlen(readline)+1 ){
if(strcmp(readline,"\n")!=0){
if( (readline[i] == ' ') && (readline[j] != ' ') ){
word_count++;
}
if( (readline[i] != ' ') && (readline[j] == '\n') ){
word_count++;
}
}
i++;
j++;
}
count++;
}
printf("current word count: %i", word_count);
return 0;
}
char* csestrcpy2(char* src){
int i = 0;
char *dest;
char t;
dest = (char*) malloc(MAX_LINE);
while( src[i] != '\0'){
dest[i] = src[i];
i++;
}
dest[i] = '\0';
//printf("length:%i\n",i);
free(dest);
return dest;
}
file_to_open
从argv
中复制出来,你可以直接使用argv
。 - user229044incoming_string=csestrcpy2(incoming_string);
您是否感到好奇?这只是一个字符串复制函数吗? - Coeffectmalloc(strlen(str+1));
几乎肯定是错误的。你可能想要写成malloc(strlen(str)+1);
。(包括我在内的许多人建议省略强制类型转换 -void *
指针将被隐式转换,如果你明确地将其转换为错误的类型,可能会导致潜在问题。) - Chris Lutz