Defining path using #define in C

Question

I want to define a path like this:

#define PATH /abc/xyz/lmn

This PATH is a directory which has files foo1, foo2, foo3, ... foo115.

How can I use this #define in the "open" call to open foo1, foo2, ... foo115 ?

I want to basically do this using the directive:

fd = open("/abc/xyz/lmn/foo1", O_RDONLY);

score 9 · Accepted Answer · answered Mar 13 '12 at 19:00

9

#define PATH "/abc/xyz/lmn"

int main (int argc, char **argv)
{
   char file2open[256];
   int i;

   for (i = 1; i <= 115; i++)
   {
      sprintf (file2open, "%sfoo%d", PATH, i);
      fd = open (file2open, O_RDONLY)
      ......
      close (fd);
   }

}

answered Mar 13 '12 at 19:00

KevinDTimm

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2

Since you're using sprintf anyway, wouldn't a const char* be better than the define? – Joachim Isaksson Mar 13 '12 at 19:07
I'm old school (maybe just old) and #define is my habit - const char* is just as good :) – KevinDTimm Mar 13 '12 at 19:15
The next question is, does the OP really want this to be a compile-time constant? Is there a chance this path will change? – John Bode Mar 13 '12 at 20:17
based upon `How can I use this #define in the "open" call to open foo1, foo2, ... foo115 ? ` I say no – KevinDTimm Mar 13 '12 at 20:19

score 1 · Answer 2 · answered Mar 13 '12 at 19:04

#define PATH "/some/path/to/foo/files"

for (int i = 0; 1 < SomeNumberOfFiles; i++)
{
    char carray[256] = strcat(PATH, "foo");
    carray = strcat(carray, char(i));
    //Do something with the carray filename
}

I may have mixed in some C++, sorry. I tried to keep it as C as a I could.

score 0 · Answer 3 · answered Mar 13 '12 at 19:14

0

For example, to open foo42 you could do:

#define PATH  "/abc/xyz/lmn"
fd = open(PATH "/foo42", O_RDONLY);

answered Mar 13 '12 at 19:14

ouah

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Defining path using #define in C

3 Answers3

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