In Go, how to print a string as a line to STDOUT? That is, the string and the newline character, nicely? And similarly, how to print the line to STDERR? In Go, you can use the ‘Println()’ func from the ‘fmt’ package to print a line to STDOUT: import(“fmt”) fmt.Println(“my msg here”) In Go, os.Stderr […]
Posts tagged golang
14 posts in total.
How to get the running process’ parent process’ ID in Go?
How to get the running process’ parent process’ ID in Go? In Go, you may call the os.Getppid() func from the os package to get the parent process’ pid. func Getppid() int Getppid returns the process id of the caller’s parent. One example is as follows. $ gore gore version 0.2.6 :help for help gore> […]
How to get the running process’ pid in Go?
How to get the running process’ pid in Go lang? In Go, you may call the os.Getpid() func from the os package to get the parent process’ pid. func Getpid() int Getppid returns the process id of the caller. One example is as follows. $ gore gore version 0.2.6 :help for help gore> :import “fmt” […]
How to get the hostname of the node in Go?
In Go lang, how to get the hostname of the node? In Go, you can use the os.Hostname() function to get the hostname of the node. func Hostname() (name string, err error) Hostname returns the host name reported by the kernel. One example is as follows. The main.go source code: package main import ( “fmt” […]
How to get the epoch timestamp in Go lang?
In Go lang, how to get the epoch timestamp, the number of seconds passed since the epoch? In Go, you can use the time.Now() func to get current time and its Unix() func to convert it into an epoch timestamp: import(“time”) func getEpochTime() int64 { return time.Now().Unix() } Answered by dtivl.
Any good Go REPL implementation / tool?
Go lang is fast to compile and can be used as a script by go run prog.go. However, a REPL is more convenient for testing/trying some small pieces of code. Any good Go REPL implementation / tool? Try gore https://github.com/motemen/gore Get gore $ go get -u github.com/motemen/gore An example $ gore gore version 0.2.6 :help […]
How to get an environment variable in Go?
In Go lang, how to get an environment variable? To get an environment variable (e.g. “VAR”) in GO: import “os” import “fmt” fmt.Println(“VAR:”, os.Getenv(“VAR”)) Answered by zma.
How to convert a byte[] to io.Reader in Go?
How to convert a byte[] to io.Reader in Go directly? You can use the NewReader() func from the bytes package of Go to convert bytes to io.Reader. For example, reader := bytes.NewReader(thebytes) Answered by Eric Z Ma.
How to read the whole file content into a string in Go?
How to read the whole file content into a string in Go? You can use the ReadFile() func from the io/ioutil package in Go to read the whole file content: func ReadFile(filename string) ([]byte, error) For example, read file filepath content and check the error: if bytes, err := ioutil.ReadFile(filepath); err != nil { log.Fatal(“Failed […]
In Golang, how to print string to STDERR?
In Golang, the fmt.Println() is convenient to print to STDOUT. But how to print string to STDERR? In Go os package, “Stdin, Stdout, and Stderr are open Files pointing to the standard input, standard output, and standard error file descriptors.” So, you can use the WriteString function on File on os.Stderr to print string to […]
In Golang, how to convert an error to a string?
In Golang, fmt.Println(err) can print out the error err. But how to convert an error to a string explicitely? In Go, the error type has an interface type error interface { Error() string } Ref: https://golang.org/pkg/builtin/#error So, for an error err, you can call err.Error() to get a string representing err. Answered by Eric Z […]
In Golang, how to convert a string to unicode rune array and back?
In Golang, how to convert a string to unicode rune array and do the reverse way? Convert string s to a rune array: runes := []rune(s) Convert a rune array runes to string: str := string(runes) Answered by Eric Z Ma.
How to process a file line by line in Go?
In the Go programming language, How to process a file line by line? An equivalent piece of Bash code could be while read line ; do echo $line done < ./input.txt You can make use of the bufio package’s Scan(). // open the file filepath f := os.Open(filepath) // create a scanner fs := bufio.NewScanner(f) […]
How to create a Reader from a string in Go?
In Go, how to create a Reader from a string? Many APIs use a Reader as its input. In Go, the strings.NewReader(s) library function creates a Reader from a string. Check the doc at: https://golang.org/pkg/strings/#NewReader Answered by Eric Z Ma.