download all pdf files

.gitignore

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+pdf

download-all-pdf.sh

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+#!/bin/bash
+
+# --------------------------------- Create the pdf directory if not exists --
+if [ ! -d pdf ]; then
+    mkdir pdf
+fi
+
+# ---------------------------------------- Add pdf directory to .gitignore --
+if [ ! -f .gitignore ]; then
+    echo pdf > .gitignore
+else
+    grep -q -F 'pdf' .gitignore || echo 'pdf' >> .gitignore
+fi
+
+# ---------------------------------------- Download pdf file if not exists --
+for f in `sed -rn 's/.*(http.+\.pdf).*/\1/pg' README.md`
+do
+    if [ ! -f "pdf/${f##*/}" ]; then
+        wget --tries=3 \
+            --timeout=5 \
+            --waitretry=1 \
+            --retry-connrefused \
+            "$f" -P pdf
+    fi
+done