How to use the ftell function in C language

This article mainly explains "how to use the ftell function in the c language". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn how to use the ftell function in the c language.

1. The C language function ftell is used to obtain the offset bytes of the current position of the file location pointer relative to the beginning of the file.

2. Get the current file size through the ftell function, and then read the buffer through the fread function.

Returns a value that returns the current value of the location identifier if successful or-1L if an error occurs.

Example

The # include # include / / fseek function calls int main () {long position; char list [100]; / * rb+ reads and writes to open a binary file that allows data to be read. * / FILE * fp = fopen ("a.txt", "rb+"); if (fp = = NULL) {printf ("file error\ n"); exit (1);} fread (list,sizeof (char), 100 dint stream); / / get position after read position=ftell (stream); printf ("Position after trying to read 100 bytes:%ld\ n", position); fclose (stream); stream=NULL; return 0 Thank you for your reading. The above is the content of "how to use the ftell function in c language". After the study of this article, I believe you have a deeper understanding of how to use the ftell function in c language, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!