见man open和man fopen:
FILE *fp;
...
fp=open(argv[1],"r");
open 返回一个整数,而不是文件指针。只需将该行更改为
fp=fopen(argv[1],"r");
注意:对于那些想知道这是什么意思的人,OP 从问题中的代码中编辑了这个错误
这导致我们(还解决了其他一些小问题 - 请参阅评论):
+编辑:指向应该进行错误检查的地方:
#include<stdio.h>
#include<string.h>
#include <errno.h>
int main(int argc, char *argv[]) {
FILE *fp;
char fline[100];
char *newline;
int i, count = 0, occ = 0;
// for starters, ensure that enough arguments were passed:
if (argc < 3) {
printf("Not enough command line parameters given!\n");
return 3;
}
fp = fopen(argv[1], "r");
// fopen will return if something goes wrong. In that case errno will
// contain the error code describing the problem (could be used with
// strerror to produce a user friendly error message
if (fp == NULL) {
printf("File could not be opened, found or whatever, errno is %d\n",errno);
return 3;
}
while (fgets(fline, 100, fp) != NULL) {
count++;
if (newline = strchr(fline, '\n'))
*newline = '\0';
if (strstr(fline, argv[2]) != NULL) {
// you probably want each found line on a separate line,
// so I added \n
printf("%s %d %s\n", argv[1], count, fline);
occ++;
}
}
// it's good practice to end your last print in \n
// that way at least your command prompt stars in the left column
printf("\n Occurence= %d", occ);
return 1;
}
ps:所以错误发生在运行时而不是编译时- 这种区别非常关键,因为寻找编译器故障和解决库使用错误需要相当不同的技术......