libgen: script to look for books in the Library Genesis

README.md

@@ -79,6 +79,7 @@ will create the symbolic link for each script in the \<path> directory.
 
 - [bor](scripts/bor) displays the latest posts from [bash.im](https://bash.im) website.
 - [ibor](scripts/ibor) displays the latest posts from [ibash.im](https://ibash.im) website.
+- [libgen](scripts/libgen) looks for books in the Library Genesis.
 - [vandroucli](scripts/vandroucli) retrieves the newest posts from the vandrouki websites ([ru](https://vandrouki.ru), [by](https://vandrouki.by), [asia](https://vandrouki.asia)).
 
 ## System

scripts/libgen

@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+
+#
+# A tiny script to look for books in the Library Genesis.
+#
+
+set -e
+set -o errtrace
+trap stacktrace ERR
+
+\unalias -a
+
+IFS=$' \t\n'
+
+function stacktrace () {
+	[ -n "$TRACED" ] && return
+
+	local depth=${#FUNCNAME[@]}
+
+	for ((i=1; i < "$depth"; i++)); do
+		printf '%*scall at %s:%s: %s()\n' "$i" '' \
+			"${BASH_SOURCE[$i]}" \
+			"${BASH_LINENO[$((i-1))]}" \
+			"${FUNCNAME[$i]}"
+	done
+
+	TRACED=true
+}
+
+libgen_search() {
+	curl -sq "${LIBGEN_SEARCH_URL}?&req=${1}&phrase=0&view=simple&column=def&sort=id&sortmode=DESC"
+}
+
+libgen_get_books_info() {
+	curl -sq "${LIBGEN_API_URL}?ids=${1}&fields=title,author,year,language,extension,md5"
+}
+
+# ------------------------------------------------------------------------------
+
+if [ -z "$1" ]; then
+	echo "USAGE: $(basename "$0") [query]" >&2
+	exit 1
+fi
+
+QUERY="$1"
+
+LIBGEN_MIRROR="https://libgen.is"
+LIBGEN_API_URL="${LIBGEN_MIRROR}/json.php"
+LIBGEN_SEARCH_URL="${LIBGEN_MIRROR}/search.php"
+LIBGEN_BOOK_URL="${LIBGEN_MIRROR}/book/index.php"
+
+rstc="\033[00m"
+magenta="\033[0;35m"
+yellow="\033[1;33m"
+blue="\033[1;34m"
+green="\033[1;32m"
+
+# ------------------------------------------------------------------------------
+
+IFS=$' ' read -r -a RAW_IDS <<<"$(libgen_search "$QUERY" | 2>&- xmllint --html --xpath "//@id[. > 0]" -)"
+
+IDS_LIST=()
+for raw_id in "${RAW_IDS[@]}"; do
+	eval "$raw_id"
+
+	# shellcheck disable=SC2154
+	IDS_LIST+=("$id")
+done
+
+IDS=$(IFS=, ; echo "${IDS_LIST[*]}")
+
+BOOKS="$(jq -r 'reverse | .[] | .author+"@"+.title+"@"+.extension+"@"+.year+"@"+.language+"@"+.md5' <<<"$(libgen_get_books_info "$IDS")")"
+
+i=1
+while IFS=$'@' read -r -a book; do
+	printf "%02d. ${green}%s${rstc}\n" "$i" "${book[1]}"
+	printf "    ${yellow}%s${rstc}, ${magenta}%s [%s]${rstc}\n" "${book[0]}" "${book[3]}" "${book[2]}"
+	printf "    ${blue}%s${rstc}\n\n" "${LIBGEN_BOOK_URL}?md5=${book[5]}"
+
+	((i++))
+done <<<"$BOOKS"
+