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从文件中读取第一行的程序
#include <stdio.h>
#include <stdlib.h> // For exit() function
int main() {
char c[1000];
FILE *fptr;
if ((fptr = fopen("program.txt", "r")) == NULL) {
printf("Error! File cannot be opened.");
// Program exits if the file pointer returns NULL.
exit(1);
}
// reads text until newline is encountered
fscanf(fptr, "%[^\n]", c);
printf("Data from the file:\n%s", c);
fclose(fptr);
return 0;
}
如果文件找到，程序会将文件内容保存到字符串 c 中，直到遇到 `'\n'` 换行符为止。
假设 `program.txt` 文件在当前目录下包含以下文本。
C programming is awesome. I love C programming. How are you doing?
程序的输出将是
Data from the file: C programming is awesome.
如果找不到 `program.txt` 文件，程序将打印错误消息。