我编写了一个代码,需要从用户指定的数据文件中读取一系列值(这可能是多达10,000行数据),这是在第一个for循环中完成的。在每行值中,其中一个变量被转换为一个字符串,该字符串定义了另一组输入文件(每个包含~20,000行数据),以便在第二个for循环中进行计算。这适用于前几百次迭代...它正确地读取所有内容,并且得到的计算(下面的代码中省略了计算,因为代码生成相同的问题,有或没有它们)是预期的。
问题是,当第一个for循环达到大约600次迭代时,它会停止并产生错误:分段错误(核心转储)
我很确定这是某种内存问题,因为如果我通过省略第二个循环中的4个输入文件来测试代码,并且它能够达到更高迭代次数....
这是代码:
#include<stdio.h>
#include<math.h>
#include<stdlib.h>
int main()
{
int num, i, j;
double X, Y;//
float Z;
char the_data[25], Z_name[10], input_1[50], input_2[50], input_3[50], input_4[50], input_5[50];
double a, b, c, d, e;
printf("Enter the name of the data file you are using:\n");
scanf("%24s", &the_data);
FILE *DATA = fopen(the_data,"r");
for (j=1; j<800; j++)
{
//***************Read data from a file, the variable Z is a floating point number which, when rounded to the nearest decimal place,
//********************determines which directory to load model data from for each value of X and Y
fscanf(DATA, "%lf %lf %f\n", &X, &Y, &Z);
//round Z to the nearest 1 decimal place
Z = Z * 10;
Z = roundf(Z);
Z = Z / 10;
//assign the full directory name to Z_name
sprintf(Z_name, "%.01fdirectory", Z);
//assign Z_name to input name string for path to the appropriate data file locations
sprintf(input_1, "./%s/a.txt", Z_name);
sprintf(input_2, "./%s/b.txt", Z_name);
sprintf(input_3, "./%s/c.txt", Z_name);
sprintf(input_4, "./%s/d.txt", Z_name);
sprintf(input_5, "./%s/e.txt", Z_name);
//Open the files
FILE *input1 = fopen(input_1, "r");
FILE *input2 = fopen(input_2, "r");
FILE *input3 = fopen(input_3, "r");
FILE *input4 = fopen(input_4, "r");
FILE *input5 = fopen(input_5, "r");
for (i=1; i < 10000; i++)
{
//For a given Z value, read in the corresponding values. Usually these input files have ~20000 values in each so the loop would be set to run until the end of the file
fscanf(input1, "%lf", &a);
fscanf(input2, "%lf", &b);
fscanf(input3, "%lf", &c);
fscanf(input4, "%lf", &d);
fscanf(input5, "%lf", &e);
}
//Test to see how far it gets in loop before giving up due to segmentation fault
printf("The iteration number is: %d\n", j);
}
printf("This will print if the program reaches the end of the first loop\n");
}
我很感激处理这个问题的任何提示或指示。谢谢!
答案 0 :(得分:2)
您需要检查fopen()
的返回值。由于您永远不会关闭输入文件,因此您可能会达到打开文件的限制。然后fopen()
返回NULL
,当您尝试将其与fscanf()
一起使用时,会出现段错误。
//Open the files
FILE *input1 = fopen(input_1, "r");
if (!input1) {
printf("open input_1 failed\n");
exit(1);
}
FILE *input2 = fopen(input_2, "r");
if (!input2) {
printf("open input_2 failed\n");
exit(1);
}
FILE *input3 = fopen(input_3, "r");
if (!input3) {
printf("open input_3 failed\n");
exit(1);
}
FILE *input4 = fopen(input_4, "r");
if (!input4) {
printf("open input_4 failed\n");
exit(1);
}
FILE *input5 = fopen(input_5, "r");
if (!input5) {
printf("open input_5 failed\n");
exit(1);
}
for (i=1; i < 10000; i++)
{
//For a given Z value, read in the corresponding values. Usually these input files have ~20000 values in each so the loop would be set to run until the end of the file
fscanf(input1, "%lf", &a);
fscanf(input2, "%lf", &b);
fscanf(input3, "%lf", &c);
fscanf(input4, "%lf", &d);
fscanf(input5, "%lf", &e);
}
//Test to see how far it gets in loop before giving up due to segmentation fault
printf("The iteration number is: %d\n", j);
fclose(input1);
fclose(input2);
fclose(input3);
fclose(input4);
fclose(input5);