77 lines
1.6 KiB
Go
77 lines
1.6 KiB
Go
package main
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import (
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"unsafe"
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"github.com/goplus/lib/c"
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"github.com/goplus/lib/c/os"
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)
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func main() {
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filename := c.Str("testfile.txt")
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data := c.Str("Hello, os!")
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var buffer [20]c.Char
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// Open a file, O_CREAT|O_WRONLY|O_TRUNC means create, write only, or clear the file
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fd := os.Open(filename, os.O_CREAT|os.O_WRONLY|os.O_TRUNC, 0644)
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if fd == -1 {
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c.Printf(c.Str("open error\n"))
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return
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}
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// Writing data to a file
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bytesWritten := os.Write(fd, c.Pointer(data), c.Strlen(data))
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if bytesWritten == -1 {
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c.Printf(c.Str("write error\n"))
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os.Close(fd)
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return
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}
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c.Printf(c.Str("Written %ld bytes to %s\n"), bytesWritten, filename)
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// Get file status flags
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flags := os.Fcntl(fd, os.F_GETFL)
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if flags == -1 {
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c.Printf(c.Str("os error\n"))
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os.Close(fd)
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return
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}
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c.Printf(c.Str("File flags: %d\n"), flags)
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// Set the file status flag to non-blocking mode
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if os.Fcntl(fd, os.F_SETFL, flags|os.O_NONBLOCK) == -1 {
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c.Printf(c.Str("os error\n"))
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os.Close(fd)
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return
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}
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c.Printf(c.Str("set file status successfully\n"))
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c.Printf(c.Str("111"))
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// Close file
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os.Close(fd)
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// Reopen the file, O_RDONLY means read-only
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fd = os.Open(filename, os.O_RDONLY)
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if fd == -1 {
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c.Printf(c.Str("open error\n"))
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return
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}
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// Reading data from a file
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// &buffer[:][0]
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// unsafe.SliceData(buffer[:])
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bytesRead := os.Read(fd, c.Pointer(unsafe.SliceData(buffer[:])), unsafe.Sizeof(buffer)-1)
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if bytesRead == -1 {
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c.Printf(c.Str("read error\n"))
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os.Close(fd)
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return
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}
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// Ensure that the buffer is null-terminated
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buffer[bytesRead] = c.Char(0)
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c.Printf(c.Str("Read %ld bytes: %s\n"), bytesRead, &buffer[0])
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// Close file
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os.Close(fd)
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}
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