Search DaniWeb - seekg()

seekg() is driving me nuts 14 Years Ago by EgyCoder …::in); binaryFile.clear(); binaryFile.seekg(32); counter=0; while …counter++; cout << endl; binaryFile.seekg( -36, ios::cur); binaryFile.read (… Re: Seekg()-problem 14 Years Ago by Pelle_3 …<< counter << std::endl; fbin.seekg(recSize * i); fbin.read(temp, sizeof(name)); if… //ask for record n = get_int(0); fbin.seekg(recSize * n); //jump to record fbin.read(…break; if (strlen(temp) != 0) counter++; } fbin.seekg(0); //reset reading position return counter; } void print_all_records() {… Re: Seekg()-problem 14 Years Ago by tetron …adding the [icode]ios::beg[/icode] [CODE]fbin.seekg(0, std::ios::beg);[/CODE] if this doesn't…;1173670]Why do I have do use the Seekg()-function two times in a row to make it… work? Code: [CODE] fbin.seekg(0); //jump to record at start of file …fbin.seekg(0); //jump to record a second time … Re: Seekg()-problem 14 Years Ago by Pelle_3 … adding the [icode]ios::beg[/icode] [CODE]fbin.seekg(0, std::ios::beg);[/CODE] if this doesn't…"; //ask for record n = get_int(0); fbin.seekg(0); fbin.seekg(recSize * n); //jump to record fbin.read(name, …0; for (int i = 0; !fbin.eof(); i++) { fbin.seekg(recSize * i); fbin.read(temp, sizeof(name)); if (strlen(temp… Re: Seekg()-problem 14 Years Ago by Pelle_3 …at your code and haven't spotted the mistake. [icode]seekg(pos)[/icode] should be setting an offset. However, I'… What I suggested before is make line 92: [CODE]fbin.seekg(recSize * n, ios::beg);[/CODE] without line 91 this …to use an offset from the explicit position start the seekg() returns a value that might be showing an error.[/… Re: seekg() is driving me nuts 14 Years Ago by WaltP I'd be more interested in knowing why you need [iCODE]seekg()[/iCODE]. This doesn't look like a binary search. Just looks like you're bouncing around a file for the sake of bouncing where just reading the file would be more efficient and less error-prone. Seekg()-problem 14 Years Ago by Pelle_3 … in a row to make it work? Code: [CODE] fbin.seekg(0); //jump to record at start of file fbin….seekg(0); //jump to record a second time (else it won'… Re: Seekg()-problem 14 Years Ago by tetron …at your code and haven't spotted the mistake. [icode]seekg(pos)[/icode] should be setting an offset. However, I'm… What I suggested before is make line 92: [CODE]fbin.seekg(recSize * n, ios::beg);[/CODE] without line 91 this says… use an offset from the explicit position start the seekg() returns a value that might be showing an error. Re: Seekg()-problem 14 Years Ago by tetron …; " " << counter << std::endl; fbin.seekg(recSize * i); fbin.read(temp, sizeof(name)); if (strlen(temp… don't understand why. As long as i write fbin.seekg(recSize * n, ios::beg), it shouldn't be of any… Re: Seekg()-problem 14 Years Ago by tetron …, but it gave no result. I actually though that the seekg and seekp functions set the absolute position in the file… Re: Seekg()-problem 14 Years Ago by Pelle_3 … don't understand why. As long as i write fbin.seekg(recSize * n, ios::beg), it shouldn't be of any… seekg() not working to find record with corresponding record number 13 Years Ago by aladar04 … using the Record Number inputted by the user. I used seekg() but it doesn't work. I have attached the files… Re: seekg() not working to find record with corresponding record number 13 Years Ago by alwaysLearning0 You have bytesPerRecord=38 but accounts.txt has different size of records which ultimately messing up your seekg calculation. Make sure all the records in account.txt is of size 38 bytes. Re: seekg() not working to find record with corresponding record number 13 Years Ago by alwaysLearning0 You have bytesPerRecord=38 but accounts.txt has different size of records which ultimately messing up your seekg calculation. Make sure all the records in account.txt is of size 38 bytes. seekg() C++ 13 Years Ago by danijela123 …]for(i=4; i<100;i=i+2){ datafile.seekg(i,ios::beg); datafile.read((char*)&dataCount,2*sizeof… Re: seekg() C++ 13 Years Ago by danijela123 …: [CODE]short spremi; // 2 byte int dataCount; // 4 byte datafile.seekg(0,ios::beg); datafile.read(reinterpret_cast<char*>(&… Re: problem with seekg 16 Years Ago by vijayan121 …n\n" ; string str ; cout.imbue( german ) ; file.seekg( namepos ) ; getline( file, str ) ; cout << …str << '\n' ; file.seekg( addresspos ) ; getline( file, str ) ; cout << str …<< '\n' ; file.seekg( phonepos ) ; getline( file, str ) ; cout << str … Re: problem with seekg 16 Years Ago by vijayan121 … the eofbit first. [CODE] file.clear() ; file.seekg( 0, std::ios::beg ) ; [/CODE] the seekg you are doing is ok because you… the beginning of the file. for a seekg to some non-zero offset (or a seekg from the end) to work reliably… Re: problem with seekg 16 Years Ago by vijayan121 …escape sequence translations during input/output. all that seekg on an fstream does is call filebuf::seekpos…quot;test.txt" ) ; // open in text mode file.seekg( 0, std::ios::beg ) ; const std::streampos beginpos =… file.tellg() ; file.seekg( 0, std::ios::end ) ; const std::streampos endpos = file… problem with seekg 16 Years Ago by jesseb07 … just before the second part to remedy that: [CODE] file.seekg (0, ios::beg); [/CODE] however, it doesn't seem to…, it says -1 whether I have the seekg there or not. to make sure seekg was the problem, I tried closing the… Re: problem with seekg 16 Years Ago by Ancient Dragon …;>then file.clear() and file.seekg(...) shouldn't work correctly either clear() and seekg() work in either binary or text mode…. seekg() just has a few limitations in text… Re: problem with seekg 16 Years Ago by vijayan121 > file.clear() and file.seekg(...) shouldn't work correctly either? >If that's the … in binary? file.clear() will work in all cases. file.seekg(...) will work in all cases if you seek to the… Re: problem with seekg 16 Years Ago by Ancient Dragon [QUOTE=vijayan121;544536] file.seekg(...) will work in all cases if you seek to the [… probably accurate, but I have no idea what it is. seekg() works the same in both text and binary mode on… Re: problem with seekg 16 Years Ago by krnekhelesh Yeah I agree with vijayan. File pointers like seekg(),tellg() work correctly only with Binary Files where the read() and write() functions are used. Re: problem with seekg 16 Years Ago by jesseb07 …; ifstream myfile ("example.txt"); begin = myfile.tellg(); myfile.seekg (0, ios::end); end = myfile.tellg(); myfile.close(); cout <… Re: problem with seekg 16 Years Ago by jesseb07 ok, so file.eof() would only work (correctly) if the file is opened in binary mode? With that in mind, then file.clear() and file.seekg(...) shouldn't work correctly either? If that's the case, is there any way I can return to the beginning of the file without opening it in binary? I appreciate the help! ~J Binary Files and Seekg 14 Years Ago by strickenUK … and then read data from the binary file and use seekg to display specific data depending on what is entered by…;< "Which Record? "; cin >> recNo; in.seekg(recNo*20 + sizeof(double), ios::beg); temp.read_in(in); cout… Re: Binary Files and Seekg 14 Years Ago by Narue … of code have the same incorrect math: [code=cplusplus] in.seekg(recNo*20 + sizeof(double), ios::beg); [/code] [code=cplusplus] int… foo = recNo * 20; in.seekg(foo + sizeof(double), ios::beg); [/code] This is painfully obvious… Re: Binary Files and Seekg 14 Years Ago by strickenUK … of code have the same incorrect math: [code=cplusplus] in.seekg(recNo*20 + sizeof(double), ios::beg); [/code] [code=cplusplus] int… foo = recNo * 20; in.seekg(foo + sizeof(double), ios::beg); [/code] This is painfully obvious… seekp & seekg is not working.... 13 Years Ago by iamcreasy … reset the position of the pointer.But, the seekp and seekg methods are not working...the pointer is not being reset… + 10*y + z; _temp << (teacherID * 100 + i); inStream.seekg(0, ios::beg); outStream.seekp(0, ios::beg); while(getline…