Increase tar --totals context, use codeblock titles + line highlights

Also remove unnecessary lines from code example

src/content/blog/race-conditions-in-signal-handlers.md

@@ -1,8 +1,17 @@
 ---
 title: "Race Conditions in Signal Handlers"
-pubDate: 2023-07-26 16:08:12 -0500
+pubDate: "2023-07-26 16:08:12 -0500"
 description: "Signals offer a unique, low-level way of communicating with processes. But under certain circumstances, they can kill processes, even when they shouldn't."
-tags: ["tar", "signals", "interrupt", "handler", "process", "unix", "race-condition"]
+tags:
+  [
+    "tar",
+    "signals",
+    "interrupt",
+    "handler",
+    "process",
+    "unix",
+    "race-condition",
+  ]
 ---
 
 Signals offer a unique, low-level way of communicating with processes. But under certain circumstances, they can kill
@@ -43,6 +52,11 @@ operations.
 By starting `tar` with the `--totals` flag, it would emit statistics upon completion. But to request
 information during the operation, a signal must be chosen, like so: `tar -x -f archive.tar --totals=SIGUSR1`.
 
+```bash
+$ tar -xf image.tar --totals
+Total bytes read: 43048960 (42MiB, 23MiB/s)
+```
+
 Emitting a signal can be done with the `kill` command, like so: `kill -USR1 <pid>`. This will send the `USR1` signal
 to the process with the given PID. The `USR1` signal is a user-defined signal, and is not used by the system.
 
@@ -50,7 +64,7 @@ And so, my plan was to start a tar process as usual with the `--totals` flag, an
 process occasionally to query an extraction operation's progress. In Python, I used the `subprocess` module to start
 and manage the process.
 
-```python
+```python {8,19}
 import os
 import subprocess
 import signal
@@ -66,13 +80,14 @@ process = subprocess.Popen(command, preexec_fn=os.setsid, stderr=subprocess.PIPE
 
 try:
     while True:
+        # Both of these don't work! Why?
+        # process.send_signal(signal.SIGUSR1)
+        # os.killpg(os.getpgid(process.pid), signal.SIGUSR1)
+
         # Ping the subprocess with SIGUSR1 signal
-        # NOTWORK: process.send_signal(signal.SIGUSR1)
-        # NOTWORK: os.killpg(os.getpgid(process.pid), signal.SIGUSR1)
         subprocess.Popen(["kill", "-SIGUSR1", str(process.pid)])
 
         print(process.stderr.readline().decode("utf-8").strip())
-        # print(process.stdout.readline().decode("utf-8").strip())
 
         # Wait for a specified interval
         time.sleep(1.9)  # Adjust the interval as needed
@@ -115,9 +130,7 @@ and of course: _signal handlers_.
 
 See below, the contents of `/proc/<pid>/status` for a process:
 
-```
+```proc title="/proc/100162/status"
-  File: /proc/100162/status
-
  1   │ Name:   Isolated Web Co
  2   │ Umask:  0002
  3   │ State:  S (sleeping)
@@ -129,13 +142,9 @@ See below, the contents of `/proc/<pid>/status` for a process:
  9   │ Uid:    1000    1000    1000    1000
 10   │ Gid:    1000    1000    1000    1000
 11   │ FDSize: 512
-  12   │ Groups: 4 27 123 1000 1001
+   
-  13   │ NStgid: 100162
-  14   │ NSpid:  100162
 ...
-  ...
+   
-  ...
-  33   │ CoreDumping:    0
 34   │ THP_enabled:    1
 35   │ Threads:    27
 36   │ SigQ:   0/62382
@@ -148,11 +157,13 @@ See below, the contents of `/proc/<pid>/status` for a process:
 43   │ CapPrm: 0000000000000000
 ```
 
+It's quite a long file (line numbers added for reference), but it contains a lot of useful information about a given process.
+
 We're interested in `SigCgt` (line 41), which is a bitmask of signals that are caught by the process. The specific bit depends on the platform, but in Python, this can be found in the signal module:
 
 ```python
 >>> from signal import SIGUSR1
->>> print(SIGUSR1)
+>>> SIGUSR1
 10
 ```