Commit 2ac4da773dcc1f487ab4b941809dce6e85259671

Refactoring in preparation for supporting multiple files
Makefile
(2 / 2)
  
11all: bs_grep
22
3bs_grep: bs_grep.cpp
4 g++ -o bs_grep bs_grep.cpp
3bs_grep: bs_grep.cpp main.cpp bs_grep.h
4 g++ -o bs_grep bs_grep.cpp main.cpp
bs_grep.cpp
(47 / 89)
  
1010OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
1111*/
1212
13#include "bs_grep.h"
14
1315#include <algorithm>
1416#include <fstream>
1517#include <sstream>
……
2525
2626using namespace std;
2727
28int64_t fieldValue(char* line, int fieldNumber);
29
30int main(int argc, char** argv)
28void reverse(char* data, int bytes)
3129{
32 char buffer[1024 * 1024];
33 int argument;
34 int fieldNumber = -1;
35 int64_t startValue = - 1;
36 int64_t endValue = -1;
37 bool reverse = false;
38 bool badArgument = false;
30 for(int i = 0; i < (bytes / 2); ++i)
31 {
32 const int other = bytes - (i + 1);
33 data[i] ^= data[other];
34 data[other] ^= data[i];
35 data[i] ^= data[other];
36 }
37}
3938
40 while((argument = ::getopt(argc, argv, "f:s:e:r")) != -1)
39int64_t fieldValue(char* line, int fieldNumber)
40{
41 std::string dump;
42 int64_t value = ~0; // to help debugging
43 const size_t count = ::strlen(line);
44 if(fieldNumber > 0)
4145 {
42 switch(argument)
46 // from left
47 istringstream stream(line);
48 for(int i = 1; i < fieldNumber; ++i)
4349 {
44 case 'f':
45 fieldNumber = atoi(::optarg);
46 break;
47 case 's':
48 startValue = atoll(::optarg);
49 break;
50 case 'e':
51 endValue = atoll(::optarg);
52 break;
53 case 'r':
54 reverse = true;
55 break;
56 case '?':
57 badArgument = true;
58 break;
59 default:
60 break;
50 stream >> dump;
6151 }
52 stream >> value;
6253 }
63 if(fieldNumber == -1 || (startValue == -1 && endValue == -1) || argc - ::optind != 1 || badArgument)
54 else
6455 {
65 cerr << "Syntax: " << argv[0] << " [-r] -f FIELDNUMBER [-s start [-e end] | -e end] FILE" << endl;
66 cerr << "\t-r Count FIELDNUMBER from the end of each line, not the start" << endl;
67 cerr << "\t-f The field number to use for the binary search" << endl;
68 cerr << "\t-s Start value" << endl;
69 cerr << "\t-e End value" << endl;
70 return 1;
56 // from right
57 // reverse the string
58 // FIXME: 8bit
59 reverse(line, count);
60 {
61 istringstream stream(line);
62 for(int i = -1; i >= fieldNumber; --i)
63 {
64 stream >> dump;
65 }
66 }
67 const char* internal = dump.c_str();
68 size_t length = strlen(internal);
69 char buffer[length];
70 ::memcpy(buffer, internal, length);
71 reverse(buffer, length);
72 value = atoll(buffer);
73 reverse(line, count);
7174 }
75 return value;
76}
77
78int bs_grep(const char* filename, int fieldNumber, int64_t startValue, int64_t endValue, bool reverse)
79{
80 char buffer[1024 * 1024];
7281 if(reverse)
7382 {
7483 fieldNumber = -fieldNumber;
7584 }
76 const char* const filename = argv[::optind];
7785
7886 struct stat fileStat;
7987 const int result = ::stat(filename, &fileStat);
……
301301 }
302302
303303 return 0;
304}
305
306void reverse(char* data, int bytes);
307
308int64_t fieldValue(char* line, int fieldNumber)
309{
310 std::string dump;
311 int64_t value = ~0; // to help debugging
312 const size_t count = ::strlen(line);
313 if(fieldNumber > 0)
314 {
315 // from left
316 istringstream stream(line);
317 for(int i = 1; i < fieldNumber; ++i)
318 {
319 stream >> dump;
320 }
321 stream >> value;
322 }
323 else
324 {
325 // from right
326 // reverse the string
327 // FIXME: 8bit
328 reverse(line, count);
329 {
330 istringstream stream(line);
331 for(int i = -1; i >= fieldNumber; --i)
332 {
333 stream >> dump;
334 }
335 }
336 const char* internal = dump.c_str();
337 size_t length = strlen(internal);
338 char buffer[length];
339 ::memcpy(buffer, internal, length);
340 reverse(buffer, length);
341 value = atoll(buffer);
342 reverse(line, count);
343 }
344 return value;
345}
346
347void reverse(char* data, int bytes)
348{
349 for(int i = 0; i < (bytes / 2); ++i)
350 {
351 const int other = bytes - (i + 1);
352 data[i] ^= data[other];
353 data[other] ^= data[i];
354 data[i] ^= data[other];
355 }
356304}