逐行读取文件-文件在哪里？

Question

Im new to using GNU C by using Terminal on a Mac.

I've used a standard piece of code to read in a file line by line and referring out to a file by "file.txt".

I can compile the source but when I execute the code it can't find file.txt. I have put the file in the the same directory as the source and executable file. Should I be adding a full directory path. I tried :-

"/Users/Swiss/documents/swdev/projects/code_ex/file.txt"

but that comes up with the same error as just using "file.txt".

The error I get is:-

-bash: ./read_file.lbl: No such file or directory

and am assuming its the file.txt it can't find - or is it something else?

The code is:-

#include <stdio.h>
int main ( void )
{
   static const char filename[] =  "/Users/Swiss/documents/swdev/projects/code_ex/file.txt";
   FILE *file = fopen ( filename, "r" );
   if ( file != NULL )
   {
      char line [ 128 ]; /* or other suitable maximum line size */
      while ( fgets ( line, sizeof line, file ) != NULL ) /* read a line */
      {
         fputs ( line, stdout ); /* write the line */
      }
      fclose ( file );
   }
   else
   {
      perror ( filename ); /* why didn't the file open? */
   }
   return 0;
}

Any help will be warmly welcomed.

Answer 1

Your program is correct. If the source file is called read_file_lbl.c , run these commands to compile it and run it from the terminal:

$ gcc -Wall -o read_file_lbl read_file_lbl.c
$ ./read_file_lbl

If you compile the program with gcc read_file_lbl.c , the compiler names the executable a.out , so trying to run ./read_file_lbl fails as no such executable is found by the shell.

Note also that gcc is really a link to clang on your environment. You can check with:

$ gcc --version