Berkeley CSUA MOTD:Entry 23592
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2025/05/27 [General] UID:1000 Activity:popular
5/27    

2002/1/18-19 [Computer/SW/Languages/C_Cplusplus] UID:23592 Activity:kinda low
1/17    In ANSI C, is there a single function call to get the size of a file?
        I only know of fseek()+ftell().  Thx.
        \_ Aren't these two not ANSI C either? They're part of the standard
           C library, but not part of the language itself. And you probably
           want to look at stat/fstat (depending on whether you've opened the
           file already). -alexf
           \_ if you want to be pedantic, yeah, but I think it's safe to
              assume that the original poster meant, "Using the ANSI C standard
              library...".
        \_ while (getc()) i++;     /* (heh) */
           \_ wrong.  EOF != 0, so even after you added the required argument
              to getc, your loop would either terminate prematurely or loop
              forever.  perhaps you meant:
                while (getc(fp) != EOF) i++;
                \_ Oh yeah... it's been several years since I did any C.
                   I'm falling back on "it's the thought that counts!".
        \_ http://www.eskimo.com/~scs/C-faq/q19.12.html
2025/05/27 [General] UID:1000 Activity:popular
5/27    

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Cache (808 bytes)
www.eskimo.com/~scs/C-faq/q19.12.html
If the size of a file'' is the number of characters you'll be able to read from it in C, it is difficult or impossible to determine this number exactly). Under Unix, the stat call will give you an exact answer. Several other systems supply a Unix-like stat which will give an approximate answer. You can fseek to the end and then use ftell, but these tend to have the same problems: fstat is not portable, and generally tells you the same thing stat tells you; Some systems provide routines called filesize or filelength, but these are not portable, either. Are you sure you have to determine the file's size in advance? Since the most accurate way of determining the size of a file as a C program will see it is to open the file and read it, perhaps you can rearrange the code to learn the size as it reads.