Difficulty with text file reader

[acartier1981]

I wrote a program to sort through 300,000 lines of formatted data in a text file to try to save some time. I am having a few problems.
1. When compiling i get a warning I have never seen before.

warning: unknown escape sequence: '\040'

2. It's either locking up or getting into an infinite loop I cant figure out. When I put it through GDB and did backtrace it showed this

0 ... in __kernel_vsyscall ()
1 ... in read () from /lib/libc.do.6
2 ... in _IO_file_underflow () from /lib/libc.so.6
3 ... in _IO_default_uflow () from /lib/libc.so.6
4 ... in __uflow () from /lib/libc.so.6
5 ... in _IO_getline_info () from /lib/libc.so.6
6 ... in _IO_getline () from /lib/libc.so.6
7 ... in fgets () from /lib/libc.so.6
8 ... in find_subrec

Any help would be greatly appreciated. I'll post some of the code if that would help but it is almost 400 lines. Thanks in advance.

[anduril462]

Yes, code would help immensely, as would providing a line number for the warning and highlighting said line in the code. You only need to post the relevant section/function. It will probably help to read up on escape sequences in C, particularly the parts about escaping a backslash and octal escape sequences.

[AndrewHunter]

That escape sequence is octal for ASCII value of the space character. It means you probably did something like this in your source code:

file = fopen("<path>\ filename") <----notice the space
vice
file=fopen("<path>\\filename") <-------no space

This could be anywhere you used a string literal with a backslash followed by a space vice a character.

EDIT: If you are going to post code just post the relevant line/section pointed to by your compiler, not all 400 lines please.

[CommonTater]

Most compilers give you a line number as part of the error message... it's probably on that line.

I'm a little curious though... if you wrote the code, how does an unknown escape sequence get into it? Unless you meant /040 ... as in division.

Post the code near the problem line (a complete function if possible) lets have a look....

[CommonTater]

PING! another triple header!

We should start a baseball team... we'd be unbeatable!

[AndrewHunter]

I'm a little curious though... if you wrote the code, how does an unknown escape sequence get into it? Unless you meant /040 ... as in division.

Because he accidentally put it in there. That is the problem with escape sequences. They are designated by a \ which is also used for path names if used incorrectly.

EDIT: No kidding. We would kick ass.

[CommonTater]

That escape sequence is octal for ASCII value of the space character. It means you probably did something like this in your source code:

file = fopen("<path>\ filename") <----notice the space
vice
file=fopen("<path>\filename") <-------no space

This could be anywhere you used a string literal with a backslash followed by a space vice a character.

EDIT: If you are going to post code just post the relevant line/section pointed to by your compiler, not all 400 lines please.

That path would require double slashing (\\) so yes that's a posibility.

[CommonTater]

Because he accidentally put it in there. That is the problem with escape sequences. They are designated by a \ which is also used for path names.

Answered before you asked!

Dang, my crystal ball is in good form tonight...

[AndrewHunter]

Answered before you asked!

Dang, my crystal ball is in good form tonight...

LOL...no kidding.

[CommonTater]

LOL...no kidding.

I just KNEW you were going to say that...

[acartier1981]

I just googled the escape sequence and fixed that. Here is the function that appears to be causing the problem

void find_subrec(FILE* ifp, FILE* ofp, char* line)
{
  char* subrec = "STARTSUBRECORD: IVSUBREC";
  char* partnum = "PARTNUMB:";
  char* temp = malloc_array(STR);

  fgets( temp, 50, ifp);
  
  while( (strncmp( temp, subrec, 24) != 0) && (strncmp( temp, partnum, 9) != 0 ) )
    fgets( temp, 50, ifp);

  while( (strncmp( temp, subrec, 24) != 0) && (strncmp( temp, partnum, 9) == 0 ) )
  {
    fprintf( ofp, "%s\n", line);
    printf("line to file\n");

    free(temp);

    line = clear_array(line, LINE);
   
    return;
  }
  free(temp);
  
  sort_vendor(ifp, ofp, line);
  
  return;
}

What I am trying to do is read through the file for lines marked like VENDOR: and PARTNUMB: then copy those lines to a string with no newline characters so when it gets printed in the new file all the information is in neat columns that I can open in excel. The system the information is coming out of wont export to spreadsheet, only to text files.

[acartier1981]

Wow you guys are fast and good, the escape sequence was a \t\ when i meant \t in a string, I should have googled that before I posted that issue sorry for that one.

[AndrewHunter]

Ok, so what line number is the compiler complaining about?

EDIT: Ok good.

[acartier1981]

The compiler isn't complaining at all about that function. I put in the printf ("line to file"); to see how far it was getting. It prints line to file 5 times before it just stops.

[CommonTater]

So long as ifp and ofp are properly opened, I don't see anything here that should be a problem...

The only thing that might be messing you up is that you are using fgets() in a function that is handing in a line to be worked on and this might displace your file pointers causing you to miss some file data... You need to create a sub-set file to test that.

On a point of form... not really an error, your function seems to be doing multiple things and might be better broken down into smaller functions... eg. 1 to locate and extract the text, 1 to handle buffer clears etc. What you have isn't wrong... but generally the best functions do one thing and do it well.