If you need to read a file line by line in Go, then you can use the bufio package as follows:
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package main
import (
"bufio"
"fmt"
"log"
"os"
)
func main() {
file, err := os.Open("/path/to/file.txt")
if err != nil {
log.Fatal(err)
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
fmt.Println(scanner.Text())
}
if err := scanner.Err(); err != nil {
log.Fatal(err)
}
}
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Just note that the Scanner will throw an error if any line has a character count longer than 65536. This relates back to a 64K size limit. In this case, you can use the Buffer method to increase the capacity.
As illustrated with the maxCapacity variable below on line 17:
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package main
import (
"bufio"
"fmt"
"log"
"os"
)
func main() {
file, err := os.Open("/path/to/file.txt")
if err != nil {
log.Fatal(err)
}
defer file.Close()
scanner := bufio.NewScanner(file)
// -- swap this variable out
const maxCapacity = longLineLen // your required line length
buf := make([]byte, maxCapacity)
// --
for scanner.Scan() {
fmt.Println(scanner.Text())
}
if err := scanner.Err(); err != nil {
log.Fatal(err)
}
}
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