How to Recover panic in Golang
Defer, Panic, and Recover in Go.
panic
During a typical panic, normal execution stops, all deferred function calls in that goroutine are executed, and the program crashes with a log message.
package main
func main() {
panic("invalid")
}
...
How to Use Deferred Function Calls in Golang
Understanding defer in Go.
Deferred Function Calls
A defer statement is an ordinary function or method call prefixed by the keyword defer. The function and argument expressions are evaluated when the statement is executed, but the actual call is def...
How to Get a SHA256 Hash from a String in Go
In Golang, using the Sum256 function is the easiest way to get a SHA256 hash from a string.Go implements several hash functions in various crypto/* packages.
Using Sum256 Function
The sha256.Sum256() function returns the SHA256 checksum of the data...
How to Get a MD5 Hash from a String in Go
In Golang, using the Sum function is the easiest way to get a MD5 hash from a string.
Using Sum Function
The md5.Sum() function returns the MD5 checksum of the data.
The following example should cover whatever you are trying to do:
package mai...
How to Check if Directory on Path is Empty in Go
In Golang, using the Readdirnames function is the easiest way to check if directory on path is empty.
Using Readdirnames Function
The file.Readdirnames(n int) function reads the contents of the directory associated with file and returns a slice of ...
How to Check if a File is a Valid Image in Go
In Golang, there are 2 ways to check if a file is a valid image.
Using DetectContentType Function
The http.DetectContentType() function implements the algorithm described at https://mimesniff.spec.whatwg.org/ to determine the Content-Type of the gi...
How to Copy a File in Go
In Golang, there are 2 ways to copy a file.
Using io.Copy Function
You can copy a file using the io.Copy() function. For example,
package main
import (
"io"
"os"
)
// Copy the src file to dst.
func Copy(src, dst string) error {
in, err...
How to Get File Length in Go
In Golang, there are 2 ways to get file length.
Using file.Stat Function
Open opens the named file for reading. If successful, methods on the returned file can be used for reading; the associated file descriptor has mode O_RDONLY.
See the followin...
How to Append Text to a File in Go
In Golang, using the os.O_APPEND flag is the easiest way to append text to a file
Using os.OpenFile Function
OpenFile is the generalized open call; most users will use Open or Create instead. It opens the named file with specified flag (O_RDONLY etc...
How to Download a Large File in Go
In Golang, using the io.copy function is the easiest way to download a large file
Using io.Copy Function
The io.Copy() function copies from src to dst until either EOF is reached on src or an error occurs. It returns the number of bytes copied and ...
How to Set Timeout for http.Get Requests in Go
In Golang, there are 2 ways to set timeout for http.Get requests
Using http.Client.Timeout Field
Timeout specifies a time limit for requests made by this Client. The timeout includes connection time, any redirects, and reading the response body.
S...
How to Read a Whole File into a String Variable in Go
In Golang, there are 3 ways to read a whole file into a string variable.
Using ioutil.ReadFile Function
ReadFile reads the file named by filename and returns the contents. A successful call returns err == nil, not err == EOF. Because ReadFile reads...
How to Read a File Line-by-Line in Go
In Golang, there are 2 ways to read a file line-by-line.
Using bufio.Scanner Function
Scanner provides a convenient interface for reading data such as a file of newline-delimited lines of text. The ones that are currently implemented are:
packa...
How many keywords are there in Go
List of Golang Keywords.
Keywords
The following keywords are reserved and may not be used as identifiers.
break default func interface select
case defer go map struct
chan else goto package switch
const ...
How to get content from a url in Go
Reading from a url resource in Go.Fetching a URL
Go provides a collection of packages, grouped under net, that make it easy to send and receive information through the Internet. Package http provides HTTP client and server implementations.
packag...