A file\'s length?
Chipset发表于 2014-03-22 07:37:00
How many bytes for a specified file?
1
2 #if (defined __unix__) || (defined _WIN64) || (defined _WIN32)
3 #include <sys/types.h>
4 #include <sys/stat.h>
5 #else
6 #include <fstream>
7 #endif
8
9 #if (defined __unix__)
10
11 unsigned long long file_length(const char* file)
12 {
13 struct stat64 st;
14 int err = stat64(file, &st);
15 if(0 != err)
16 return 0;
17 return static_cast<unsigned long long>(st.st_size);
18 }
19
20 #elif (defined _WIN32) || (defined _WIN64)
21
22 // Microsoft has some extensions to support Unix!
23 unsigned long long file_length(const char* file)
24 {
25 struct __stat64 st;
26 int err = _stat64(file, &st);
27 if(0 != err)
28 return 0;
29 return static_cast<unsigned long long>(st.st_size);
30 }
31
32 #else
33
34 // the last alternative
35 unsigned long long file_length(const char* file)
36 {
37 std::ifstream fin(file, std::ios_base::in);
38 if(!fin.is_open())
39 return 0;
40 fin.seekg(0, std::ios_base::beg);
41 std::ifstream::pos_type pos_start = fin.tellg();
42 fin.seekg(0, std::ios_base::end);
43 std::ifstream::pos_type pos_end = fin.tellg();
44 return static_cast<unsigned long long>(pos_end - pos_start);
45 }
46
47 #endif
48
2 #if (defined __unix__) || (defined _WIN64) || (defined _WIN32)
3 #include <sys/types.h>
4 #include <sys/stat.h>
5 #else
6 #include <fstream>
7 #endif
8
9 #if (defined __unix__)
10
11 unsigned long long file_length(const char* file)
12 {
13 struct stat64 st;
14 int err = stat64(file, &st);
15 if(0 != err)
16 return 0;
17 return static_cast<unsigned long long>(st.st_size);
18 }
19
20 #elif (defined _WIN32) || (defined _WIN64)
21
22 // Microsoft has some extensions to support Unix!
23 unsigned long long file_length(const char* file)
24 {
25 struct __stat64 st;
26 int err = _stat64(file, &st);
27 if(0 != err)
28 return 0;
29 return static_cast<unsigned long long>(st.st_size);
30 }
31
32 #else
33
34 // the last alternative
35 unsigned long long file_length(const char* file)
36 {
37 std::ifstream fin(file, std::ios_base::in);
38 if(!fin.is_open())
39 return 0;
40 fin.seekg(0, std::ios_base::beg);
41 std::ifstream::pos_type pos_start = fin.tellg();
42 fin.seekg(0, std::ios_base::end);
43 std::ifstream::pos_type pos_end = fin.tellg();
44 return static_cast<unsigned long long>(pos_end - pos_start);
45 }
46
47 #endif
48