Merge pull request #181 from codecrafters-io/printing-matches

Grep/Printing Matches

Author: UdeshyaDhungana

.gitignore

@@ -1,2 +1,5 @@
 course-definition-tester
 .history/
+
+# MacOS
+.DS_Store

course-definition.yml

@@ -76,6 +76,13 @@ extensions:
       Along the way, you'll learn about how to implement the `*` quantifier (zero or more), and bounded quantifiers.
       [1]: https://learn.microsoft.com/en-us/dotnet/standard/base-types/quantifiers-in-regular-expressions
 
+  - slug: "printing-matches"
+    name: "Printing Matches"
+    description_markdown: |
+      In this challenge extension, you'll add support for printing matching lines to your Grep implementation.
+
+      Along the way, you'll learn about extracting matched lines, formatting output, and managing line-by-line processing.
+
 stages:
   - slug: "cq2"
     name: "Match a literal character"
@@ -304,3 +311,17 @@ stages:
     difficulty: hard
     marketing_md: |-
       In this stage, we'll add support for `{n,m}`, the [between n and m times](https://docs.microsoft.com/en-us/dotnet/standard/base-types/quantifiers-in-regular-expressions#match-between-n-and-m-times-nm) quantifier.
+
+  - slug: "ku5"
+    primary_extension_slug: "printing-matches"
+    name: "Print a single matching line"
+    difficulty: easy
+    marketing_md: |-
+      In this stage, you'll add support for printing a single input line if it matches the pattern.
+
+  - slug: "pz6"
+    primary_extension_slug: "printing-matches"
+    name: "Print multiple matching lines"
+    difficulty: easy
+    marketing_md: |-
+      In this stage, you'll add support for printing multiple input lines if they match the pattern.

stage_descriptions/printing-matches-01-ku5.md

@@ -0,0 +1,33 @@
+In this stage, you'll add support for printing a single input line if it matches the pattern.
+
+### Printing the input line
+
+If the input line matches the pattern, Grep prints the line to the standard output.
+
+Example usage:
+
+```bash
+$ echo -n "apple" | ./your_program.sh -E "[^abc]"
+apple
+```
+
+### Tests
+
+The tester will execute your program like this:
+
+```bash
+$ echo -n "dog" | ./your_program.sh -E "dog$"
+```
+
+If the input line does not match the specified pattern, your program must:
+- Exit with the code 1
+- Exit with no printed output
+
+If the input line matches the specified pattern, your program must:
+- Exit with the code 0
+- Print the input line to the standard output
+
+
+### Notes
+
+- The tester will only test against a single input line. You don't need to process multiple input lines in this stage. We'll get to that in the next stage.

stage_descriptions/printing-matches-02-pz6.md

@@ -0,0 +1,34 @@
+In this stage, you'll add support for printing multiple input lines if they match the pattern.
+
+### Printing multiple matching lines
+
+If multiple input lines are provided, grep prints all the matching lines to the standard output.
+
+Example usage:
+
+```bash
+$ echo -ne "line1\nline_two\nline3" | grep -E "\d"
+line1
+line3
+```
+
+### Tests
+
+The tester will execute your program like this:
+
+```bash
+$ echo -ne "first_line\n2nd_line\n3rd_line" | ./your_program.sh -E "\d"
+```
+
+If none of the input lines match the specified pattern, your program must:
+- Exit with the code 1
+- Exit with no printed output
+
+If at least one input line matches the specified pattern, 
+- Exit with the code 0
+- Print all the matching input lines to the standard output
+
+
+### Notes
+
+- You should print all the matching lines to the standard output.