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|
package main
import (
"crypto/tls"
"fmt"
"io"
"net/url"
"os"
"tildegit.org/tjp/sliderule"
"tildegit.org/tjp/sliderule/gemini"
)
const usage = `Resource fetcher for the small web.
Usage:
sw-fetch (-h | --help)
sw-fetch [-v | --verbose] [-o PATH | --output PATH] [-k | --keyfile PATH] [ -c | --certfile PATH ] [ -s | --skip-verify ] URL
Options:
-h --help Show this screen.
-v --verbose Display more diagnostic information on standard error.
-o --output PATH Send the fetched resource to PATH instead of standard out.
-k --keyfile PATH Path to the TLS key file to use.
-c --certfile PATH Path to the TLS certificate file to use.
-s --skip-verify Don't verify server TLS certificates.
`
func main() {
conf := configure()
cl := sliderule.NewClient(conf.clientTLS)
response, err := cl.Fetch(conf.url.String())
if err != nil {
fail(err.Error() + "\n")
}
defer func() {
_ = response.Close()
_ = conf.output.Close()
}()
_, _ = io.Copy(conf.output, response.Body)
}
type config struct {
verbose bool
output io.WriteCloser
url *url.URL
clientTLS *tls.Config
}
func configure() config {
if len(os.Args) == 1 {
fail(usage)
}
conf := config{output: os.Stdout}
key := ""
cert := ""
verify := true
for i := 1; i <= len(os.Args)-1; i += 1 {
switch os.Args[i] {
case "-h", "--help":
os.Stdout.WriteString(usage)
os.Exit(0)
case "-v", "--verbose":
conf.verbose = true
case "-o", "--output":
if i+1 == len(os.Args)-1 {
fail(usage)
}
out := os.Args[i+1]
if out != "-" {
output, err := os.OpenFile(out, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
if err != nil {
fmt.Println(err.Error())
failf("'%s' is not a valid path\n", out)
}
conf.output = output
}
i += 1
case "-k", "--keyfile":
if i+1 == len(os.Args)-1 {
fail(usage)
}
i += 1
key = os.Args[i]
case "-c", "--certfile":
if i+1 == len(os.Args)-1 {
fail(usage)
}
i += 1
cert = os.Args[i]
case "-s", "--skip-verify":
verify = false
}
}
conf.clientTLS = &tls.Config{}
if key != "" || cert != "" {
if key == "" || cert == "" {
fail("-k|--keyfile and -c|--certfile must both be present, or neither\n")
}
tlsConf, err := gemini.FileTLS(cert, key)
if err != nil {
failf("failed to load TLS key pair")
}
conf.clientTLS = tlsConf
}
conf.clientTLS.InsecureSkipVerify = !verify
u, err := url.Parse(os.Args[len(os.Args)-1])
if err != nil || u.Scheme == "" {
fail(usage)
}
conf.url = u
return conf
}
func fail(msg string) {
os.Stderr.WriteString(msg)
os.Exit(1)
}
func failf(msg string, args ...any) {
fmt.Fprintf(os.Stderr, msg, args...)
os.Exit(1)
}
|
