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 file/stream objects on which they operate. On Linux, seekg and fseek are probably implemented in …

fseek(f, 0, SEEK_END); // seek to end of file size = ftell(f); // get current file pointer fseek(f, 0, SEEK_SET); // seek back to beginning of file // proceed with allocating memory and reading the file Linux/POSIX: You can use stat (if you know the filename), or fstat (if you have the file descriptor). Here is an example for stat:

See here: fseek. The fseek() function shall allow the file-position indicator to be set beyond the end of existing data in the file. If data is later written at this point, subsequent reads of data in the gap shall return bytes with the value 0 until data is actually written into the gap. That's why fseek cannot return EOF.

2018年5月10日 · But get this: ONLY fseek() allows you to seek from the beginning of the file, from your current position in the file, and backwards from the end of the file (the third argument to fseek() being SEEK_SET, SEEK_CUR, and SEEK_END). fsetpos() doesn't do this. fsetpos() is limited to going back to some position you got from fgetpos().

2014年1月15日 · This relies on POSIX functionality (fstat) rather than plain C, and it's less reliable.For instance, if the "file" is /dev/sda1, fstat will show 0 size, but the fseek/ftell method will get the size of the partition.

Some details become complicated, however, and fseeking is one of them. Because of this, the C standard only defines fseek in text files in a few cases: to the very beginning, to the very end, to the current position, and to a previous position that has been retrieved with ftell. In other words, you can't compute a location to seek to for text ...

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 make sure you check the return value from fopen().

2012年1月18日 · need of fseek() in c. 2. unsure of fseek syntax in c. 0. I can't understand what a fseek parameter does. 0.

2014年8月15日 · You can successfully use fseek on stdout if and only if stdout refers to a seekable stream.. If your program's standard output is going to a terminal or something similar (which is typically the default) or to a pipe, then fseek will fail.

2014年2月21日 · fseek (fp, 0, SEEK_END); or feof(fp); Basically i just went till end of file and directly without printing the original contents of file and tried printing the reversed content of file. But for it does not print the reversed content filed either !!! it just display blank.