From bc65345f6e5cb6bfd10ee1b7a8a4f7f8da447c41 Mon Sep 17 00:00:00 2001
From: Dave Molk <davemolk@gmail.com>
Date: Mon, 5 Dec 2022 06:05:53 -0700
Subject: [PATCH] add rp

---
 README.md    |  3 +++
 rp/main.go   | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 rp/readme.md | 33 +++++++++++++++++++++++
 rp/urls.txt  |  4 +++
 4 files changed, 116 insertions(+)
 create mode 100644 rp/main.go
 create mode 100644 rp/readme.md
 create mode 100644 rp/urls.txt

diff --git a/README.md b/README.md
index 5513e83..676be09 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,9 @@ parse urls in style. read urls from a line-separated file or from stdin. Get dom
 ## pw
 need a kinda sorta safe(ish?) password and too lazy to log into your pw manager or some rando genderating rando site? type something in and get a mostly gibberish password that contains at least one lower-case letter, one upper-case, one special character, and one number. there are, of course, much easier ways to do this -- I was mainly interested in practicing pipelines :)
 
+## rp
+replace a key=value parameter in a given URL(s) with your own key=value. Bonus! Pipe in an encoded mess and decode it.
+
 ## tas
 throw against site (pull down archived links from Wayback Machine, run against the site, see what status codes currently are)
 
diff --git a/rp/main.go b/rp/main.go
new file mode 100644
index 0000000..13f0604
--- /dev/null
+++ b/rp/main.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"log"
+	"net/url"
+	"os"
+	"strings"
+)
+
+func main() {
+	var d bool
+	var kv string
+	flag.BoolVar(&d, "d", false, "decode query string(s)")
+	flag.StringVar(&kv, "kv", "", "given key, replace value(s)")
+	flag.Parse()
+
+	if !d && kv == "" {
+		log.Fatal("must select d or v")
+	}
+	
+	exit := make(chan struct{})
+	if d {
+		go decode(exit)
+	} else {
+		go replaceValue(exit, kv)
+	}
+
+	<-exit
+}
+
+func decode(exit chan struct{}) {
+	defer close(exit)
+	s := bufio.NewScanner(os.Stdin)
+	for s.Scan() {
+		d, err := url.QueryUnescape(s.Text())
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Println(d)
+	}
+	if err := s.Err(); err != nil {
+		fmt.Println(err)
+	}
+}
+
+func replaceValue(exit chan struct{}, kv string) {
+	defer close(exit)
+
+	p := strings.Split(kv, "=")
+	if len(p) != 2 {
+		log.Fatal("must supply input as key=value")
+	}
+	key := p[0]
+	value := p[1]
+
+	s := bufio.NewScanner(os.Stdin)
+	for s.Scan() {
+		u, err := url.ParseRequestURI(s.Text())
+		if err != nil {
+			log.Println(err)
+			continue
+		}
+		params := u.Query()
+
+		params.Set(key, value)
+		
+		u.RawQuery = params.Encode()
+		fmt.Println(u.String())
+	}
+	if err := s.Err(); err != nil {
+		fmt.Println(err)
+	}
+}
\ No newline at end of file
diff --git a/rp/readme.md b/rp/readme.md
new file mode 100644
index 0000000..95278db
--- /dev/null
+++ b/rp/readme.md
@@ -0,0 +1,33 @@
+# replace params
+Replace a key=value parameter in a given URL(s) with your own key=value. Bonus! Pipe in an encoded mess and decode it.
+
+## Flags
+```
+-q: query parameter as key=value 
+-d: decode mode 
+```
+
+## Test URLs
+```
+https://example.com/foo/bar?first=1&second=2
+https://example.com/bar?foo=me&baz=barz
+https://www.google.com/search?name=golang&language=en&mascot=gopher&foo=bar
+google.com
+```
+
+## Usage
+(replace a value)
+```
+cat urls.txt | rp -v foo=bar
+https://example.com/foo/bar?first=1&foo=bar&second=2 // adds &foo=bar
+https://example.com/bar?baz=barz&foo=bar // overwrites value for preexisting key
+https://www.example.com/rp?foo=bar&language=en&mascot=gopher&name=golang // kv already exists
+2022/12/05 05:52:44 parse "google.com": invalid URI for request // no thanks
+```
+
+(decode query string(s))
+```
+echo "cart=%5B%5B0%2C+%7B%22logo%22%3A+%22kitten.jpg%22%2C+%22price%22%3A+0%2C+%22name%22%3A+%22Kitten%22%2C+%22desc%22%3A+%228%5C%22x10%5C%22+color+glossy+photograph+of+a+kitten.%22%7D%5D%2C+%5B0%2C+%7B%22logo%22%3A+%22kitten.jpg%22%2C+%22price%22%3A+0%2C+%22name%22%3A+%22Kitten%22%2C+%22desc%22%3A+%228%5C%22x10%5C%22+color+glossy+photograph+of+a+kitten.%22%7D%5D%2C+%5B1%2C+%7B%22logo%22%3A+%22puppy.jpg%22%2C+%22price%22%3A+0%2C+%22name%22%3A+%22Puppy%22%2C+%22desc%22%3A+%228%5C%22x10%5C%22+color+glossy+photograph+of+a+puppy.%22%7D%5D%5D" | rp -d
+
+cart=[[0, {"logo": "kitten.jpg", "price": 0, "name": "Kitten", "desc": "8\"x10\" color glossy photograph of a kitten."}], [0, {"logo": "kitten.jpg", "price": 0, "name": "Kitten", "desc": "8\"x10\" color glossy photograph of a kitten."}], [1, {"logo": "puppy.jpg", "price": 0, "name": "Puppy", "desc": "8\"x10\" color glossy photograph of a puppy."}]]
+```
\ No newline at end of file
diff --git a/rp/urls.txt b/rp/urls.txt
new file mode 100644
index 0000000..de49b6b
--- /dev/null
+++ b/rp/urls.txt
@@ -0,0 +1,4 @@
+https://example.com/foo/bar?first=1&second=2
+https://example.com/bar?foo=me&baz=barz
+https://www.example.com/rp?name=golang&language=en&mascot=gopher&foo=bar
+google.com
\ No newline at end of file