fwrite

I've got a question regarding programming and files. while(current!=NULL) { if(current->Id_Doctor!='\0') { current=current->next; id_doc=(current->Id_Doctor); } if(current->Id_Doctor=='\0') { id_doc=id_doc+1; printf("%d", id_doc); break; } } fwrite(&id_doc, sizeof(char), 1, Archivo); I dont know why but it aint writing the value of id_doc on the binary file called 'Archivo'...what could be the problem? I added a printf of id_doc and the value was printed..I really dont know Ok, heres the full code(more-less): struct Medico { int Id_Doctor; int Estado; char Nombre[60]; char Clave_Acceso[20];

I'm using a large array of floats. After a lot of fiddling I've managed to write it to a binary file. When opening that file at a later time, the reading process only reads a couple of handfuls of floats (according to the return-value of fread(), and it's all values 0.0f). The reading is supposed to put the floats into an (the original) array, and it does not contain the original values. I'm using Code::Blocks and MinGW doing a program in the 32bit realm on a 64bit pc .. and I'm not very proficient on c/c++ and pointers. #include<...> const int mSIZE = 6000 ; static float data[mSIZE*mSIZE] ;

This question already has an answer here: Writing and reading (fwrite - fread) structures with pointers 3 answers gcc (GCC) 4.7.0 c89 Hello, I have the following structure that I am trying to fwrite and fread. However, because my device and resource are pointers. The fwrite will read the pointer values and not the data. I cannot use a array for the device or resource. Only pointers as they have to be dynamically allocated. I allocate all memory for the structure elements before I write. Not shown here as I want to keep the snippet short. Nor is free'ing. In my fread function, I allocate the

I wrote a very simple file corruptor for fun, but to my surprise, the "corrupted" file ends up being smaller in size than the original. Here is the corruption function that is supposed to replace bytes but not to delete them: void corruptor(char *inputname, int percent) { FILE *input; FILE *output; int filesize; char *outputname = append_name(inputname); // Duplicate file cp(outputname, inputname); // Open input and output input = fopen(inputname, "r"); if (input == NULL) { printf("Can't open input, errno = %d\n", errno); exit(0); } output = fopen(outputname, "w+"); if (output == NULL) {

I have a struct member as a char * and assign it to a string literal "John" on the struct initialisation as shown below. The string prints fine with printf. However, if I write this string to a file using fwrite, in the file I read back garbage. If I use a char array instead of a char * (commented out in the struct as shown), and write it to the file, I can read back the string in the file as expected. I can't understand this. Shouldn't fwrite in both cases take the pointer and write the correct string to the file? Furthermore , if I declare a separate char * and point it to a string literal

Since fwrite() cannot apply encoding argument , how can i export csv file in specific encode as fast as fwrite() ? ( fwrite() is the fastest function within my acknowledgement so far) fwrite(DT,"DT.csv",encoding = "UTF-8") Error in fwrite(DT, "DT.csv", encoding = "UTF-8") : unused argument (encoding = "UTF-8") user2554330 You should post a reproducible example, but I would guess you could do this by making sure the data in DT is in UTF-8 within R, then setting the encoding of each column to "unknown". R will then assume the data is encoded in the native encoding when you write it out. For

How can you open a text file and append all its lines to another text file in C++? I find mostly solutions for separate reading from a file to a string, and writing from a string to a file. Can this elegantly be combined? It is not always given that both files exist. There should be a bool return when accessing each of the files. I'm sorry if this is already off-topic: Is appending text content to a file conflict-free in the meaning that multiple programs can do this simultaneously (the order of the lines DOESN'T matter) ? If not, what would be an (atomic) alternative? jrd1 I can only speak