关于字符串：C-将反向文件内容打印到stdout

C - print reversed file contents to stdout

我想读取文件的内容并打印其内容的反面。仅使用fopen，fgets，fputs，fclose。这是我所做的，但是没有打印任何内容。

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#include <sys/types.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <unistd.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
if (argc != 2)
{
return 1;
}
FILE *f = fopen(argv[1],"r");
if (f == NULL)
{
return 2;
}
char buffer[4096];
char reversed[4096];
char *line = fgets(buffer, 50, f); //read 50 characters at a time
int length = 0;
int j = 0;
while (line != NULL) // while end of file not reached
{
length = 0;
j = 0;
for (char *temp = buffer; *temp != '\\0'; temp++) //find length of buffer
{
length += 1;
}
for (int i = length; i > 0; i--) // reverse buffer
{
reversed[j] = buffer[i];
j += 1;
}
fputs(reversed, stdout);
line = fgets(buffer, 50, f);
}
fclose(f);
return 0;
}

输出：

(nothing)

例：

1 2	abcdef ghi

预期输出：

1 2	fedcba ihg