shellcheck on gosher -- a few checks disabled

2 files changed, 49 insertions, 41 deletions

diff --git a/README.md b/README.md
index 7480473..aad1da0 100644
--- a/README.md
+++ b/README.md
@@ -23,19 +23,19 @@ gophermap.
 
 ## Which netcat?
 
-There are currently several different implementations of `netcat`, and
-each of them works in a slightly different way and/or offers a different
-set of options. For the sake of using `gosher`, the main issue is
-whether your `netcat` implementation does exit or not when its standard
-input gets closed.  Notably, the original `netcat` implementation by
-hobbit@avian.org does **not** exit, while other common implementations
-(OpenBSD `netcat`, `ncat` from the nmap project, and GNU `netcat`)
-normally do.  The current version of `gosher` can work with different
-implementations of `netcat`, provided that the variable `NETCAT` points
-to the `netcat` version you want to use, and that the variable `STYLE`
-in `gosher` is set correctly. In particular, `STYLE` can pe set equal to
-either 'pipe' or 'fork'. Please check below what is the recommended
-combination for your version of `netcat`:
+There are currently several different implementations of `netcat(1)`,
+and each of them works in a slightly different way and/or offers a
+different set of options. For the sake of using `gosher`, the main issue
+is whether your `netcat(1)` implementation does exit or not when its
+standard input gets closed.  Notably, the original `netcat(1)`
+implementation by hobbit@avian.org does **not** exit, while other common
+implementations (OpenBSD `netcat(1)`, `ncat(1)` from the nmap project,
+and GNU `netcat(1)`) normally do.  The current version of `gosher` can
+work with different implementations of `netcat(1)`, provided that the
+variable `NETCAT` points to the `netcat(1)` version you want to use, and
+that the variable `STYLE` in `gosher` is set correctly. In particular,
+`STYLE` can pe set equal to either 'pipe' or 'fork'. Please check below
+what is the recommended combination for your version of `netcat(1)`:
 
 	+----------------+--------------+--------------+
 	| netcat version | STYLE='fork' | STYLE='pipe' |
@@ -51,18 +51,19 @@ combination for your version of `netcat`:
 the 'fork' mode is a potential security risk**
 
 
-## Running `gosher` under `chroot`
+## Running `gosher` under `chroot(8)`
 
-In general, it makes sense to run a server in a `chroot` environment, to
+In general, it makes sense to run a server in a `chroot(8)` environment, to
 reduce the risks connected with remote exploits. If you would like to
-run `gosher` under `chroot` be sure to have the following binaries (and
+run `gosher` under `chroot(8)` be sure to have the following binaries (and
 the corresponding libs) available in the chroot-ed environment:
 
 ```
-	basename cat cut mkfifo netcat realpath rm sed sh
+	basename(1) cat(1) cut(1) dirname(1) mkfifo(1) netcat(1) realpath(1)
+	rm(1) sed(1) sh(1) which(1)
 ```
 
-Obviously, `netcat` will be your preferred `netcat` implementation. 
+Obviously, `netcat(1)` will be your preferred `netcat(1)` implementation. 
 
 
 ## Why `gosher`?
diff --git a/gosher b/gosher
index 3dda536..45161b9 100755
--- a/gosher
+++ b/gosher
@@ -58,13 +58,13 @@ DEBUG=
 
 ## function
 cleanup(){
-	[ -n "$INF"  ] &&  [ -p "$INF"  ] && rm -f ${INF}
+	[ -n "$INF"  ] &&  [ -p "$INF"  ] && rm -f "${INF}"
 	exit 1
 }
 
-MYNAME=$(basename $0)
-MYDIR=$(dirname $(realpath $0))
-NETCAT=$(which $NETCAT)
+MYNAME=$(basename "$0")
+MYDIR=$(dirname "$(realpath "$0")")
+NETCAT=$(which "$NETCAT")
 
 if [ -z "${MYNAME#gosher}" ]; then
 	## we are called as gosher -- launch the server
@@ -72,27 +72,30 @@ if [ -z "${MYNAME#gosher}" ]; then
 	PORT=${1:-70}
 	GOPHERDIR=${2:-"./"}
 	
-	[ ! -f "${NETCAT}" -o ! -x "${NETCAT}" ] && {
+	[ ! -f "${NETCAT}" ] || [ ! -x "${NETCAT}" ] && {
 		echo "Wrong NETCAT -- Exiting" >&2
 		exit 2
 	}
 	
-	if [ -f "${MYDIR}/gosher_serve" -o -h "${MYDIR}/gosher_serve" ]; then
+	if [ -f "${MYDIR}/gosher_serve" ] ||  [ -h "${MYDIR}/gosher_serve" ]; then
 		GOSHER_SERVE="${MYDIR}/gosher_serve"
 		trap cleanup 0 HUP INT TRAP TERM QUIT
 	
-		INF=${IPREFIX}$$
+		INF="${IPREFIX}$$"
 		[ "$STYLE" = "pipe" ] && {
-			mkfifo -m 600 $INF
+			mkfifo -m 600 "$INF"
+# shellcheck disable=SC2050
 			while [ 1 -eq 1 ]; do
-				${GOSHER_SERVE} ${GOPHERDIR} <$INF | ${NETCAT} -vvvvv -l -p ${PORT} >$INF
+# shellcheck disable=SC2094
+				${GOSHER_SERVE} "${GOPHERDIR}" <"$INF" | ${NETCAT} -vvvvv -l -p "${PORT}" >"$INF"
 			done
 			rm -f $INF
 			exit 0
 		}
 		[ "$STYLE" = 'fork' ] && {
+# shellcheck disable=SC2050
 			while [ 1 -eq 1 ]; do
-				${NETCAT} -vv -l -p $PORT -c "${GOSHERSERVE} ${GOPHERDIR}"
+				${NETCAT} -vv -l -p "$PORT" -c "${GOSHER_SERVE} ${GOPHERDIR}"
 			done
 			exit 0
 		}
@@ -115,6 +118,7 @@ fi
 invalid_selector(){
 	sel="$1"
 	echo "3Error: Invalid selector: \"$sel\""
+# shellcheck disable=SC1117
 	printf ".\r\n"
 	exec 1>&-
 	exec 2>&-
@@ -139,19 +143,20 @@ serve_index(){
         IDX=$1
         IFS='
 '
-        while read line; do
-                rline=$(echo $line | sed -r -e 's/\r//g')
-                case $rline in
+        while read -r line; do
+                rline=$(echo "$line" | sed -r -e 's/\r//g')
+                case "$rline" in
                         '['*)
-                                echo $rline | sed -r -e 's/\[//g;s/\]//g;s/\|/\t/g;s/\t//;s/$/\r/g'
+                                echo "$rline" | sed -r -e 's/\[//g;s/\]//g;s/\|/\t/g;s/\t//;s/$/\r/g'
                         ;;
                        t*)
-                               echo $rline | cut -c 2-
+                               echo "$rline" | cut -c 2-
                        ;;
                         *)
-                                echo $line
+                                echo "$line"
                 esac
-        done < $IDX
+        done < "$IDX"
+# shellcheck disable=SC1117
 	printf ".\r\n"
 	exec 1>&-
 	exec 2>&-
@@ -183,9 +188,9 @@ EOF
 
 GOPHERDIR=${1:-"./"}
 
-read selector
+read -r selector
 
-selector=$(echo $selector | sed -r 's:\$.*::g;s:\r::g' )
+selector=$(echo "$selector" | sed -r 's:\$.*::g;s:\r::g' )
 
 [ -n "$DEBUG" ] && {
 	echo "iGOPHERDIR: ${GOPHERDIR}"
@@ -194,13 +199,15 @@ selector=$(echo $selector | sed -r 's:\$.*::g;s:\r::g' )
 
 case $selector in
 	URL:*)
-		url=$(echo $selector | cut -d ":" -f 2-)
-		serve_redirect $url
+		url=$(echo "$selector" | cut -d ":" -f 2-)
+		serve_redirect "$url"
         ;;
 	/?*|"")
 		RP1=$(realpath "${GOPHERDIR}"/"${selector}" || "")
+# shellcheck disable=SC2181
 		[ $? -eq 0 ] || invalid_selector "$selector"
 		RP2=$(realpath "${GOPHERDIR}")"${selector}"
+# shellcheck disable=SC2181
 		[ $? -eq 0 ] || invalid_selector "$selector"
 		[ -n "$DEBUG" ] && {
 			echo "iRP1: ${RP1}"
@@ -209,8 +216,8 @@ case $selector in
 		
 		if [ "${RP1}" = "${RP2}" ]; then
 			if [ -f "${RP1}" ]; then
-				if [ -n "$(echo $RP1 | sed -n '/\.gph$/p')" ]; then 
-					serve_index $RP1
+				if [ -n "$(echo "${RP1}" | sed -n '/\.gph$/p')" ]; then 
+					serve_index "${RP1}"
 				else
 					serve_selector "${RP1}"
 				fi