Make fixes recommended by shellcheck

ci/validate.sh

@@ -3,6 +3,6 @@
 set -eu
 
 for file in src/*.md ; do
-    echo Checking references in $file
-    cargo run --quiet --bin link2print < $file > /dev/null
+    echo Checking references in "$file"
+    cargo run --quiet --bin link2print < "$file" > /dev/null
 done

tools/convert-quotes.sh

@@ -5,7 +5,7 @@ set -eu
 mkdir -p tmp/src
 rm -rf tmp/*.md
 
-for f in src/${1:-""}*.md
+for f in src/"${1:-\"\"}"*.md
 do
     cargo run --bin convert_quotes < "$f" > "tmp/$f"
     mv "tmp/$f" "$f"

tools/doc-to-md.sh

@@ -3,7 +3,7 @@
 set -eu
 
 # Get all the docx files in the tmp dir.
-ls tmp/*.docx | \
+find tmp -name '*.docx' -print0 | \
 # Extract just the filename so we can reuse it easily.
 xargs -n 1 basename -s .docx | \
 while IFS= read -r filename; do

tools/megadiff.sh

@@ -12,7 +12,7 @@ rm -rf tmp/book-after/css/ tmp/book-after/theme/ tmp/book-after/img/ tmp/book-af
       tmp/book-after/*.json tmp/book-after/print.html
 
 # Get all the html files before
-ls tmp/book-before/*.html | \
+find tmp/book-before -name '*.html' -print0 | \
 # Extract just the filename so we can reuse it easily.
 xargs -n 1 basename | \
 while IFS= read -r filename; do

tools/nostarch.sh

@@ -12,7 +12,7 @@ rm -rf tmp/markdown
 MDBOOK_OUTPUT__MARKDOWN=1 mdbook build -d tmp
 
 # Get all the Markdown files
-ls tmp/markdown/${1:-""}*.md | \
+find tmp/markdown -name "${1:-\"\"}*.md" -print0 | \
 # Extract just the filename so we can reuse it easily.
 xargs -n 1 basename | \
 # Remove all links followed by `<!-- ignore -->``, then

tools/update-rustc.sh

@@ -3,18 +3,18 @@
 set -eu
 
 # Build the book before making any changes for comparison of the output.
-echo 'Building book into `tmp/book-before` before updating...'
+echo 'Building book into tmp/book-before before updating...'
 mdbook build -d tmp/book-before
 
 # Rustfmt all listings
 echo 'Formatting all listings...'
 find -s listings -name Cargo.toml -print0 | while IFS= read -r -d '' f; do
-    dir_to_fmt=$(dirname $f)
+    dir_to_fmt=$(dirname "$f")
 
     # There are a handful of listings we don't want to rustfmt and skipping
     # doesn't work; those will have a file in their directory that explains why.
     if [ ! -f "${dir_to_fmt}/rustfmt-ignore" ]; then
-        cd $dir_to_fmt
+        cd "$dir_to_fmt"
         cargo fmt --all && true
         cd - > /dev/null
     fi
@@ -30,42 +30,42 @@ root_dir=$(pwd)
 echo 'Regenerating output...'
 # For any listings where we show the output,
 find -s listings -name output.txt -print0 | while IFS= read -r -d '' f; do
-    build_directory=$(dirname $f)
+    build_directory=$(dirname "$f")
     full_build_directory="${root_dir}/${build_directory}"
     full_output_path="${full_build_directory}/output.txt"
     tmp_build_directory="tmp/${build_directory}"
 
-    cd $tmp_build_directory
+    cd "$tmp_build_directory"
 
     # Save the previous compile time; we're going to keep it to minimize diff
     # churn
-    compile_time=$(sed -E -ne 's/.*Finished (dev|test) \[unoptimized \+ debuginfo] target\(s\) in ([0-9.]*).*/\2/p' ${full_output_path})
+    compile_time=$(sed -E -ne 's/.*Finished (dev|test) \[unoptimized \+ debuginfo] target\(s\) in ([0-9.]*).*/\2/p' "${full_output_path}")
 
     # Save the hash from the first test binary; we're going to keep it to
     # minimize diff churn
-    test_binary_hash=$(sed -E -ne 's@.*Running [^[:space:]]+ \(target/debug/deps/[^-]*-([^\s]*)\)@\1@p' ${full_output_path} | head -n 1)
+    test_binary_hash=$(sed -E -ne 's@.*Running [^[:space:]]+ \(target/debug/deps/[^-]*-([^\s]*)\)@\1@p' "${full_output_path}" | head -n 1)
 
     # Act like this is the first time this listing has been built
     cargo clean
 
     # Run the command in the existing output file
-    cargo_command=$(sed -ne 's/$ \(.*\)/\1/p' ${full_output_path})
+    cargo_command=$(sed -ne 's/$ \(.*\)/\1/p' "${full_output_path}")
 
     # Clear the output file of everything except the command
-    echo "$ ${cargo_command}" > ${full_output_path}
+    echo "$ ${cargo_command}" > "${full_output_path}"
 
     # Regenerate the output and append to the output file. Turn some warnings
     # off to reduce output noise, and use one test thread to get consistent
     # ordering of tests in the output when the command is `cargo test`.
-    RUSTFLAGS="-A unused_variables -A dead_code" RUST_TEST_THREADS=1 $cargo_command >> ${full_output_path} 2>&1 || true
+    RUSTFLAGS="-A unused_variables -A dead_code" RUST_TEST_THREADS=1 $cargo_command >> "${full_output_path}" 2>&1 || true
 
     # Set the project file path to the projects directory plus the crate name
     # instead of a path to the computer of whoever is running this
-    sed -i '' -E -e 's@(Compiling|Checking) ([^\)]*) v0.1.0 (.*)@\1 \2 v0.1.0 (file:///projects/\2)@' ${full_output_path}
+    sed -i '' -E -e 's@(Compiling|Checking) ([^\)]*) v0.1.0 (.*)@\1 \2 v0.1.0 (file:///projects/\2)@' "${full_output_path}"
 
     # Restore the previous compile time, if there is one
     if [ -n  "${compile_time}" ]; then
-        sed -i '' -E -e "s/Finished (dev|test) \[unoptimized \+ debuginfo] target\(s\) in [0-9.]*/Finished \1 [unoptimized + debuginfo] target(s) in ${compile_time}/" ${full_output_path}
+        sed -i '' -E -e "s/Finished (dev|test) \[unoptimized \+ debuginfo] target\(s\) in [0-9.]*/Finished \1 [unoptimized + debuginfo] target(s) in ${compile_time}/" "${full_output_path}"
     fi
 
     # Restore the previous test binary hash, if there is one
@@ -73,7 +73,7 @@ find -s listings -name output.txt -print0 | while IFS= read -r -d '' f; do
         replacement='s@Running ([^[:space:]]+) \(target/debug/deps/([^-]*)-([^\s]*)\)@Running \1 (target/debug/deps/\2-'
         replacement+="${test_binary_hash}"
         replacement+=')@g'
-        sed -i '' -E -e "${replacement}" ${full_output_path}
+        sed -i '' -E -e "${replacement}" "${full_output_path}"
     fi
 
     # Clean again
@@ -83,7 +83,7 @@ find -s listings -name output.txt -print0 | while IFS= read -r -d '' f; do
 done
 
 # Build the book after making all the changes
-echo 'Building book into `tmp/book-after` after updating...'
+echo 'Building book into tmp/book-after after updating...'
 mdbook build -d tmp/book-after
 
 # Run the megadiff script that removes all files that are the same, leaving only files to audit