我正在尝试在C代码中使用动态内存。我正在使用struct而我做错了什么，但我无法弄清楚是什么。第一部分是我的标题（.h）文件的一部分，我在其中定义了两个结构。
第二部分是我的C（.c）文件的一部分，我初始化结构并使用它。我得到一个seg错误，ddd告诉我那个seg。注释后出现故障：这是seg的所在。发生故障。 任何帮助都将非常感激
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第一部分
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#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <math.h>
void parseFile(FILE * fp, FILE * sketcher);
void processArgument(char argument[]);
void printOutput();
#define MAX_WORD 256
#define initial_size 17
extern const char argument[];
FILE* popen(const char*, const char*);
int pclose(FILE*);
struct pointxy {
double x;
double y;
};
struct figure{
char figureName[MAX_WORD];
struct pointxy vertices[17];
int countPoints;
};
struct figure figurehere[17];
struct figure newFigure[17];
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第二部分
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#include "draw2.h"
#include "draw2a.h"
#include "memwatch.h"
struct figure *figureHere;
void printOutput(){
printf("./draw2 started on:");
fflush(stdout);
system("date\n");
}
/*send what ever there is after the child to sketchpad(in that specific line)*/
void child (char line[], char word[], char nameFigure[], FILE * sketcher){
sscanf(line, "%s%s", word, nameFigure);
fprintf (sketcher, "%s\n", &line[6]);
}
/*I construct the struct by reading from the Figure line to the end figure line.*/
struct figure* figureFunction (FILE * fp, char line[], char word[], char figureName[], int countNumberoffigures){
double startx, starty;
int temp = 1;
sscanf(line, "%s%s%lf%lf%s", word, figureName, &startx, &starty, word);
figureHere->vertices[0].x = startx;
figureHere->vertices[0].y = starty;
strcpy(figureHere->figureName, figureName);
fgets(line, MAX_WORD - 1, fp);
int nuRead = sscanf(line, "%s", word);
int i = 1;
while (strncmp(word, "End", MAX_WORD)!=0){
if (strncmp(word, "#", MAX_WORD) == 0){
printf("%s",line);
}
if (strncmp(word, "draw", MAX_WORD) == 0){
sscanf (line, "%s%lf%lf", word, &startx, &starty);
figureHere->vertices[i].x = figureHere->vertices[i-1].x + startx;
figureHere->vertices[i].y = figureHere->vertices[i-1].y + starty;
i += 1;
}
fgets(line, MAX_WORD - 1, fp);
nuRead = sscanf(line, "%s", word);
}
figureHere->countPoints = i;
return figureHere;
}
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第三部分
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#include "draw2.h"
#include "draw2a.h"
#include "draw2b.h"
#include "memwatch.h"
struct figure myFigures[17];
struct figure **pointsAndname;
const char Exec_c[] = "java -jar Sketchpad.jar";
void parseFile(FILE * fp, FILE *sketcher){
char line [MAX_WORD], word [MAX_WORD], figureName [MAX_WORD];
int countNumberoffigures; //accounts to which figure in the array we are on
printOutput();
int temp = 1;
countNumberoffigures = 0;
while ( fgets(line, MAX_WORD - 1, fp) != NULL ){
int nuRead = sscanf(line, "%s", word);
if ( nuRead > 0 ){
if(strncmp(word, "Figure", MAX_WORD)==0){ //1)reads the figure, name and the two starting points
countNumberoffigures += 1; //accounts to which figure in the array we are on
pointsAndname = malloc(sizeof(struct figure*)*temp);
pointsAndname[countNumberoffigures -1] = figureFunction(fp,line, word, figureName, countNumberoffigures);
}
if(strncmp(word, "printFigure", MAX_WORD)==0){ //4)read the command printFigure, name of the figure
printFigure(fp, line, countNumberoffigures);
}
if(strncmp(word, "drawFigure", MAX_WORD)==0){ //5)read the command drawFigure and the name of the figure
drawFigure(sketcher, line, countNumberoffigures);
}
if(strncmp(word, "translate", MAX_WORD)==0){ //6)read the command translate
translate(line, sketcher, countNumberoffigures);
}
if(strncmp(word, "child", MAX_WORD)==0){ //7)reads command child and the name of the figure
child(line, word, figureName, sketcher);
}
if(strncmp(word, "#", MAX_WORD)==0){ //8)reads the whole line until the \n
printf(line);
//printf("ani po\n");
}
if(strncmp(word, "end", MAX_WORD)==0){
fprintf (sketcher, "end\n");
//printf("ani po\n");
}
if(strncmp(word, "rotate", MAX_WORD)==0){
rotate(line, sketcher, countNumberoffigures);
}
}
}
}
void processArgument(char argument[]){
FILE *sketcher;
FILE *fp;
fp = fopen (argument, "r");
sketcher = popen(Exec_c, "w");
if (sketcher == NULL){
printf ("Could not open pipe to %s\n", argument);
}else{
parseFile(fp, sketcher);
fclose(fp);
if (pclose(sketcher) == -1){
fprintf(stderr, "draw_line error: couldn't close pipe to %s.\n", Exec_c);
exit(EXIT_FAILURE);
}
}
}
int main (int argc, char *argv[]){
int i;
if ( argc < 2 ){
printf ("%s\n", "0 comment(s)");
}else{
for (i = 1; i < argc; i++){
processArgument(argv[i]);
}
}
//int *a = malloc(sizeof(int));
return 0;
}
答案 0 :(得分：3)
在你的头文件中，你要声明一个静态的数字数组：
struct figure figurehere[17];
但是在你的实现文件（* .c）中，你正在用
创建一个指向'figure'的单独指针struct figure *figureHere;
现在，从技术上讲，这些是完全独立的，figurehere和figureHere都可以在您的实现文件中访问，因为C区分大小写...但是，我想这可能不是故意的你的部分，最后可能被认为是不好的做法，因为它很可能在快速阅读代码时容易混淆或误导。我建议，如果你打算将它们作为完全独立的变量，那么你将它们命名为更明显不同。
然而，前面的评论中所说的是正确答案：您正在声明一个指针figureHere，并且在没有初始化它的情况下使用它。
....我假设您打算figureHere（大写字母H）指向figurehere（较低的H），我已经写了一个解释，但后来我意识到这个问题具体提及malloc。遗憾的是，malloc甚至没有出现在您的代码中，所以我不确定该用法是如何“错误”的，除非没有用。代码是否丢失，或者您是否无法正确使用malloc创建figure figureHere来指向？
编辑/附加：
重新阅读我注意到您具体说的问题
第一部分是我的一部分 标题（.h）文件，我在其中定义了两者 我的结构。
这个真的让我相信你打算让figurehere和figureHere成为同一个数组。要实现这一目标，您有以下几种选择：
1）删除figureHere，然后直接使用figurehere。因为你已经将figurehere声明为全局（许多人会说你很糟糕，但这是一个完全不同的主题），你可以直接访问它而不需要任何指针。
2）初始化figureHere以指向figurehere。您只需将声明更改为
struct figure *figureHere = figurehere;