ENXIO 这是SEEK_DATA或SEEK_HOLE,当前的文件偏移超出了文件的结尾。 遵守: POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD. 注意: 有关文件描述符,打开文件描述和文件之间关系的讨论,请参阅open(2)。 有些设备无法搜索,POSIX也没有指定哪些设备必须支持lseek()。 在Linux上,在终端设备上使用lseek()将返回ESPIPE...
lseek（）函数用于调整与指定文件描述符关联的打开文件的偏移位置。它通过接受三个参数：文件描述符、偏移量以及定位方式（如绝对位置、当前位置或文件末尾）来实现这一目标。描述：lseek（）函数的操作基于三种偏移定位方式：1. SEEK_SET：偏移量设置为偏移字节的绝对位置。2. SEEK_CUR：偏移量设置为当前...
SEEK_HOLE always return the offset of the end of the file, and making SEEK_DATA always return offset (i.e., even if the location referred to by offset is a hole, it can be considered to consist of data that is a sequence of zeros). The _GNU_SOURCE feature test macro must be defi...
代码实现 # 打开文件file=open('example.txt','r')# 定位到指定行line_number=10# 从第10行开始读取file.seek(0)# 移动文件指针到文件开头for_inrange(line_number-1):file.readline()# 读取并丢弃前line_number - 1行# 读取数据data=file.read()print(data)# 关闭文件file.close() 1. 2. 3. 4. ...
如果whence 是 SEEK_SET,文件偏移量将被设置为 offset。 如果whence 是 SEEK_CUR,文件偏移量将被设置为 cfo 加上 offset,offset 可以为正也可以为负 如果whence 是 SEEK_END,文件偏移量将被设置为文件长度加上 offset, offset 可以为正也可以为负
/* write some data to the file */ write(handle, msg, strlen(msg));/* seek to the begining of the file */ lseek(handle, 0L, SEEK_SET);/* reads chars from the file until we hit EOF */ do { read(handle, &ch, 1);printf("%c", ch);} while (!eof(handle));clo...
(3).SEEK_END: 当前位置为文件结尾,新位置为偏移量大小 返回值:文件新的偏移值 二、利用lseek()产生空洞文件(hole) 说明: 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 ...
SEEK_CUR 文件中的当前文件偏移量 SEEK_END 文件的结尾 大型文件支持 z/OS UNIX 文件:AMODE 64 C/C++ 应用程序自动支持大型 z/OS UNIX 文件。 AMODE 31 C/C++ 应用程序必须使用long long data type supportenabled进行编译,并在包含任何头之前定义 _LARGE_FILES 功能测试宏,以使此函数能够在大小大于 2 GB...
After you have used lseek() to seek to a new location, the next I/O operation on the file begins at that location.lseek() lets you specify new file offsets past the current end of the file. If data is written at such a point, read operations in the gap between this data and the...
SEEK_DATA, the offset is set to the start of the next non-hole file region greater than or equal to the supplied offset. The lseek() system call allows the file offset to be set beyond the end of the existing end-of-file of the file. If data is later written at this point, ...