Parser: fix config parser

README.md

@@ -37,12 +37,29 @@ coronation:
     Hostname: coronation.cs.ualberta.ca
 ```
 
-## Rules
+## Quick Start
+
+```bash
+mv ~/.ssh/config ~/.ssh/config_og
+python3 src/ssh_config_to_yaml.py ~/.ssh/config_og --out ~/.ssh/config.yaml
+# Do some edits on ~/.ssh/config.yaml. The migration script won't compress
+# things with for-loops or templates. Then...
+python3 ~/.ssh/config.yaml --out ~/.ssh/config
+```
+
+As a proof of concept, you can even chain the scripts! The order of hosts will
+change, but the config should function identically!
+
+```bash
+python3 src/main.py <(python3 src/ssh_config_to_yaml.py ~/.ssh/config)
+```
+
+# Rules
 
 The `src/ssh_config_to_yaml.py` script will assist in quickly migrating your
 existing config.
 
-#### SSH Properties
+### SSH Properties
 
 Standard SSH config properties go under the `ssh_props` heading for every host.
 For example:
@@ -72,7 +89,7 @@ github.com:
 Note that yaml does not support duplicate keys, so keys can take a list of
 properties instead to mimic repeated keys, as seen above.
 
-#### Templates
+### Templates
 
 Templates are "default" properties inherited from another host. Templates must
 be declared above the host that uses it. You can make a template-only host by
@@ -153,7 +170,7 @@ Host ohaton
     LocalForward 9000 localhost:9000
 ```
 
-#### For loops
+### For loops
 
 For loops allow simple substitution of a single variable over a range or set of
 values. Ranges must be numerical, but sets can be any arbitrary string. Multiple

src/ssh_config_to_yaml.py

@@ -0,0 +1,58 @@
+import argparse
+import json
+import re
+import yaml
+from pathlib import Path
+
+parser = argparse.ArgumentParser(description="Process some integers.")
+parser.add_argument("file", type=Path, help="yaml config")
+parser.add_argument("--json", action="store_true", help="output parse as json")
+parser.add_argument("--out", type=Path, help="write into file")
+
+args = parser.parse_args()
+
+
+def parse_sshconfig(lines):
+    parse = dict()
+    hostname = None
+    host = dict()
+
+    re_host = re.compile(r"^\s*Host (.+)$")
+    re_prop = re.compile(r"^\s*([A-Za-z]+)[ =](.+)$")
+
+    for line in lines:
+        m_host = re_host.match(line)
+        m_prop = re_prop.match(line)
+
+        if m_host:
+            if hostname is not None:
+                parse[hostname] = { "ssh_props": host }
+
+            hostname = m_host[1]
+            host = dict()
+        elif m_prop and host.get(m_prop[1]):
+            host[m_prop[1]].append(m_prop[2])
+        elif m_prop:
+            host[m_prop[1]] = [m_prop[2]]
+
+    if hostname is not None:
+        parse[hostname] = { "ssh_props": host }
+
+    return parse
+
+
+# ╔───────────────────────────────────────────────────────────────────────────╗
+# │ Mαiη                                                                      |
+# ╚───────────────────────────────────────────────────────────────────────────╝
+with open(args.file, "r") as f:
+    lines = f.read().splitlines()
+
+parse = parse_sshconfig(lines)
+
+if args.json:
+    print(json.dumps(parse))
+elif args.out:
+    with open(args.out, "w") as f:
+        f.write(yaml.dump(parse))
+else:
+    print(yaml.dump(parse), end="")