Updated SC2026 (markdown)

SC2026.md

@@ -1,24 +1,37 @@
-## Consider using grep -c instead of grep|wc.
+## This word is outside of quotes. Did you intend to 'nest '"'single quotes'"' instead'?
 
 ### Problematic code:
 
-    grep foo | wc -l
+    alias server_uptime='ssh $host 'uptime -p''
 
 ### Correct code:
 
-    grep -c foo
+    alias server_uptime='ssh $host '"'uptime -p'"
 
 ### Rationale:
 
-This is purely a stylistic issue. `grep` can count lines without piping to `wc`. 
+In the first case, the user has four single quotes on a line, wishfully hoping that the shell will match them up as outer quotes around a string with literal single quotes:
 
-Note that in many cases, this number is only used to see whether there are matches (i.e. `> 0`). In these cases, it's better and more efficient to use `grep -q` and check its exit status:
+                        v--------match--------v
+    alias server_uptime='ssh $host 'uptime -p''
+                                   ^--match--^  
 
-    if grep -q pattern file
-    then
-      echo "The file contains the pattern"
-    fi
+The shell, meanwhile, always terminates single quoted strings at the first possible single quote:
+
+                        v---match--v
+    alias server_uptime='ssh $host 'uptime -p''
+                                             ^^
+
+Which is the same thing as `alias server_uptime='ssh $host uptime' -p`.
+
+There is no way to nest single quotes. However, single quotes can be placed literally in double quotes, so we can instead concatenate a single quoted string and a double quoted string:
+
+                        v--match---v
+    alias server_uptime='ssh $host '"'uptime -p'"
+                                    ^---match---^
+
+This results in an alias with embedded single quotes. 
 
 ### Exceptions
 
-If you e.g. want to count characters instead of lines, and you actually care about the number and not just whether it's greater than 0.
+None.