Understanding functioning of read () and lseek () in C
2017年4月3日 · Since read() and lseek() are system calls, they shall correspond to changes in updated file if kernel/OS buffer regularly syncs with file in Hard disk. But that is not the case. …
what's the difference between `fseek`, `lseek`, `seekg`, `seekp`?
2012年2月19日 · Use fseek when using the C stdio library. Use lseek when using low-level POSIX file descriptor I/O. The difference between the various seek functions is just the kind of …
seek - C Program: How to properly use lseek() or fseek() to modify …
2010年10月18日 · Regardless, lseek and fseek aren't going to jump to the correct spot unless you know where that is. Additionally, if you increase the record size (for instance when you add 1 …
c - Read/write from file descriptor at offset - Stack Overflow
2013年11月5日 · Yes, you can use lseek(): off_t lseek(int fd, off_t offset, int whence); The lseek() function repositions the offset of the open file associated with the file descriptor fd to the …
c - Whats the difference between this lseek, fseek, read, fread ...
2012年1月17日 · I also noticed that the standard input version was the one you said was working correctly. If you're having trouble with the FILE * version, I suspect the fopen() call is failing, so …
Getting file size with lseek command in c - Stack Overflow
2018年8月28日 · Since you didn't check that the open() succeeded, the most likely problem is that you didn't open the file successfully, and therefore the lseek() fails and reports -1. You've only …
Using lseek system call in C to read a structure written in a file
2019年9月23日 · I have written a structure Student into a file and read the whole structure to the console. Now, I want to reposition the file pointer to read information about a specific student. I …
c - reset the file location using lseek () system call - Stack Overflow
2019年9月2日 · I tried to use the system call lseek() to get back the beginning of a file or reach the end of the file. The exact code I used is: int location = lseek(fd, 0, SEEK_SET) //get back …
c - How to properly use lseek() to extend file size ... - Stack Overflow
2017年1月6日 · The lseek() function allows the file offset to be set beyond the end of the file (but this does not change the size of the file). If data is later written at this point, subsequent reads …
memory - Getting a file's size in C with lseek? - Stack Overflow
2016年10月27日 · lseek() does not work from a filename. It expects an integer file handle. Try stat() instead. Additionally, don't use a pointer return value.