Created Sc2046 (markdown)

Sc2046.md

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+# Quote this to prevent word splitting
+
+### Problematic code:
+
+    ls -l $(getfilename)
+
+### Correct code:
+
+    # getfilename outputs 1 file
+    ls -l "$(getfilename)"
+
+    # getfilename outputs multiple files, linefeed separated
+    getfilename | while IFS='' read -r line
+    do
+      ls -l "$line"
+    done
+
+### Rationale:
+
+When command expansions are unquoted, word splitting and globbing will occur. This often manifests itself by breaking when filenames contain spaces. 
+
+Trying to fix it by adding quotes or escapes to the data will not work. Instead, quote the command substitution itself. 
+
+If the command substitution outputs multiple pieces of data, use a loop instead.
+
+### Contraindications
+
+In rare cases you actually want word splitting, such as in 
+
+    gcc $(pkg-config --libs openssl) client.c
+
+This is because `pkg-config` outputs `-lssl -lcrypto`, which you want to break up by spaces into `-lssl` and `-lcrypto`.