解析 C 中的命令行参数
我正在尝试编写一个程序，可以比较两个文件逐行，逐字，或字符的字符在 C。它必须能够读取命令行选项 -l，-w，-i或 --..。
- 如果选项是
-l，它将逐行比较文件。 - 如果选项是
-w，则逐字比较文件。 - 如果该选项是
--，它会自动假设下一个参数是第一个文件名。 - 如果选项是
-i，则以不区分大小写的方式对它们进行比较。 - 默认值为逐字符比较文件。
只要 -w和 -l不是同时输入的，并且不多于或少于两个文件，输入选项的次数并不重要。
我甚至不知道从哪里开始解析命令行参数。
这就是我想出来的所有代码。我还没有完全检查错误，但是我是否以过于复杂的方式写东西？
/*
* Functions to compare files.
*/
int compare_line();
int compare_word();
int compare_char();
int case_insens();
/*
* Program to compare the information in two files and print message saying
* whether or not this was successful.
*/
int main(int argc, char* argv[])
{
/* Loop counter */
size_t i = 0;
/* Variables for functions */
int caseIns = 0;
int line = 0;
int word = 0;
/* File pointers */
FILE *fp1, *fp2;
/*
* Read through command-line arguments for options.
*/
for (i = 1; i < argc; i++)
{
printf("argv[%u] = %s\n", i, argv[i]);
if (argv[i][0] == '-')
{
if (argv[i][1] == 'i')
{
caseIns = 1;
}
if (argv[i][1] == 'l')
{
line = 1;
}
if (argv[i][1] == 'w')
{
word = 1;
}
if (argv[i][1] == '-')
{
fp1 = argv[i][2];
fp2 = argv[i][3];
}
else
{
printf("Invalid option.");
return 2;
}
}
else
{
fp1(argv[i]);
fp2(argv[i][1]);
}
}
/*
* Check that files can be opened.
*/
if(((fp1 = fopen(fp1, "rb")) == NULL) || ((fp2 = fopen(fp2, "rb")) == NULL))
{
perror("fopen()");
return 3;
}
else
{
if (caseIns == 1)
{
if(line == 1 && word == 1)
{
printf("That is invalid.");
return 2;
}
if(line == 1 && word == 0)
{
if(compare_line(case_insens(fp1, fp2)) == 0)
return 0;
}
if(line == 0 && word == 1)
{
if(compare_word(case_insens(fp1, fp2)) == 0)
return 0;
}
else
{
if(compare_char(case_insens(fp1,fp2)) == 0)
return 0;
}
}
else
{
if(line == 1 && word == 1)
{
printf("That is invalid.");
return 2;
}
if(line == 1 && word == 0)
{
if(compare_line(fp1, fp2) == 0)
return 0;
}
if(line == 0 && word == 1)
{
if(compare_word(fp1, fp2) == 0)
return 0;
}
else
{
if(compare_char(fp1, fp2) == 0)
return 0;
}
}
}
return 1;
if(((fp1 = fclose(fp1)) == NULL) || (((fp2 = fclose(fp2)) == NULL)))
{
perror("fclose()");
return 3;
}
else
{
fp1 = fclose(fp1);
fp2 = fclose(fp2);
}
}
/*
* Function to compare two files line-by-line.
*/
int compare_line(FILE *fp1, FILE *fp2)
{
/* Buffer variables to store the lines in the file */
char buff1 [LINESIZE];
char buff2 [LINESIZE];
/* Check that neither is the end of file */
while((!feof(fp1)) && (!feof(fp2)))
{
/* Go through files line by line */
fgets(buff1, LINESIZE, fp1);
fgets(buff2, LINESIZE, fp2);
}
/* Compare files line by line */
if(strcmp(buff1, buff2) == 0)
{
printf("Files are equal.\n");
return 0;
}
printf("Files are not equal.\n");
return 1;
}
/*
* Function to compare two files word-by-word.
*/
int compare_word(FILE *fp1, FILE *fp2)
{
/* File pointers */
FILE *fp1, *fp2;
/* Arrays to store words */
char fp1words[LINESIZE];
char fp2words[LINESIZE];
if(strtok(fp1, " ") == NULL || strtok(fp2, " ") == NULL)
{
printf("File is empty. Cannot compare.\n");
return 0;
}
else
{
fp1words = strtok(fp1, " ");
fp2words = strtok(fp2, " ");
if(fp1words == fp2words)
{
fputs(fp1words);
fputs(fp2words);
printf("Files are equal.\n");
return 0;
}
}
return 1;
}
/*
* Function to compare two files character by character.
*/
int compare_char(FILE *fp1,FILE *fp2)
{
/* Variables to store the characters from both files */
int c;
int d;
/* Buffer variables to store chars */
char buff1 [LINESIZE];
char buff2 [LINESIZE];
while(((c = fgetc(fp1))!= EOF) && (((d = fgetc(fp2))!=EOF)))
{
if(c == d)
{
if((fscanf(fp1, "%c", buff1)) == (fscanf(fp2, "%c", buff2)))
{
printf("Files have equivalent characters.\n");
return 1;
break;
}
}
}
return 0;
}
/*
* Function to compare two files in a case-insensitive manner.
*/
int case_insens(FILE *fp1, FILE *fp2, size_t n)
{
/* Pointers for files. */
FILE *fp1, *fp2;
/* Variable to go through files. */
size_t i = 0;
/* Arrays to store file information. */
char fp1store[LINESIZE];
char fp2store[LINESIZE];
while(!feof(fp1) && !feof(fp2))
{
for(i = 0; i < n; i++)
{
fscanf(fp1, "%s", fp1store);
fscanf(fp2, "%s", fp2store);
fp1store = tolower(fp1store);
fp2store = tolower(fp2store);
return 1;
}
}
return 0;
}
