Adds new version of help50

Dockerfile

@@ -177,11 +177,13 @@ RUN apt update && \
         ca-certificates \
         clang \
         clang-format \
+        colorized-logs `# For help50` \
         coreutils `# For fold` \
         cowsay \
         curl \
         dos2unix \
         dnsutils `# For nslookup` \
+        expect `# For help50` \
         fonts-noto-color-emoji `# For render50` \
         gdb \
         git \
@@ -251,7 +253,6 @@ RUN pip3 install --no-cache-dir \
         cs50 \
         Flask \
         Flask-Session \
-        help50 \
         pytest \
         render50 \
         setuptools \

Makefile

@@ -13,7 +13,7 @@ rebuild:
 	docker build --build-arg VCS_REF=$(shell git rev-parse HEAD) --no-cache --tag $(IMAGE) .
 
 run:
-	docker run --env LANG=$(LANG) --env LOCAL_WORKSPACE_FOLDER="$(PWD)" --interactive --publish-all --rm --security-opt seccomp=unconfined --tty --volume "$(PWD)":/mnt --volume /var/run/docker.sock:/var/run/docker-host.sock --workdir /mnt $(IMAGE) bash --login || true
+	docker run --env LANG=$(LANG) --env LOCAL_WORKSPACE_FOLDER="$(PWD)" --env WORKDIR=/mnt --interactive --publish-all --rm --security-opt seccomp=unconfined --tty --volume "$(PWD)":/mnt --volume /var/run/docker.sock:/var/run/docker-host.sock --workdir /mnt cs50/cli bash --login || true
 
 squash: depends
 	docker-squash --tag $(IMAGE) $(IMAGE)

etc/profile.d/cli.sh

@@ -1,5 +1,5 @@
 # If not root
-if [ "$(whoami)" != "root" ]; then
+if [ `id -u` -ne 0 ]; then
 
     # $PATH
     export PATH="/opt/cs50/bin":"/opt/bin":"$PATH"
@@ -60,4 +60,9 @@ if [ "$(whoami)" != "root" ]; then
 
     # Valgrind
     export VALGRIND_OPTS="--memcheck:leak-check=full --memcheck:show-leak-kinds=all --memcheck:track-origins=yes"
+
+    ## TODO: Start help50 if enabled
+    if help50 is-enabled > /dev/null; then
+        help50 start
+    fi
 fi

etc/profile.d/help50.sh

@@ -0,0 +1,127 @@
+# If not started
+if [[ -z "$HELP50" ]]; then
+    return
+fi
+
+# Directory with helpers
+HELPERS="/opt/cs50/lib/help50"
+
+# Library
+. /opt/cs50/lib/cli
+
+# Ignore duplicates (but not commands that begin with spaces)
+export HISTCONTROL="ignoredups"
+
+function _help50() {
+
+    # Get exit status of last command
+    local status=$?
+
+    # Get last command line, independent of user's actual history
+    histfile=$(mktemp)
+    HISTFILE=$histfile history -a
+    local argv=$(HISTFILE=$histfile history 1 | cut -c 8-) # Could technically contain multiple commands, separated by ; or &&
+    rm --force $histfile
+
+    # Remove aliases
+    for name in n no y yes; do
+        unalias $name 2> /dev/null
+    done
+
+    # If last command erred (and is not ctl-c or ctl-z)
+    # https://tldp.org/LDP/abs/html/exitcodes.html
+    if [[ $status -ne 0 && $status -ne 130 && $status -ne 148 ]]; then
+
+        # Ignore ./* if executable file
+        local argv0=$(echo "$argv" | awk '{print $1}') # Assume for simplicity it's just a single command
+        if [[ "$argv0" =~ ^\./ && -f "$argv0" && -x "$argv0" ]]; then
+            return
+        fi
+
+        # Read typescript from disk
+        local typescript=$(cat $HELP50)
+
+        # Remove script's own output (if this is user's first command)
+        typescript=$(echo "$typescript" | sed '1{/^Script started on .*/d}')
+
+        # Cap typescript at MIN(1K lines, 1M bytes), else `read` is slow
+        typescript=$(echo "$typescript" | head -n 1024 | cut -b 1-1048576)
+
+        # Remove any line continuations from command line
+        local lines=""
+        while IFS= read -r line || [[ -n "$line" ]]; do
+            if [[ -z $done && $line =~ \\$ ]]; then
+                lines+="${line%\\}"
+            else
+                lines+="$line"$'\n'
+                local done=1
+            fi
+        done <<< "$typescript"
+        typescript="$lines"
+
+        # Remove command line from typescript
+        typescript=$(echo "$typescript" | sed '1d')
+
+        # Remove ANSI characters
+        typescript=$(echo "$typescript" | ansi2txt)
+
+        # Remove control characters
+        # https://superuser.com/a/237154
+        typescript=$(echo "$typescript" | col -bp)
+
+        # Try to get help
+        for helper in $HELPERS/*; do
+            if [[ -f $helper && -x $helper ]]; then
+                local help=$($helper $argv <<< "$typescript")
+                if [[ -n "$help" ]]; then
+                    break
+                fi
+            fi
+        done
+        if [[ -n "$help" ]]; then # If helpful
+            _helpful "$help"
+        elif [[ $status -ne 0 ]]; then # If helpless
+            _helpless "$typescript"
+        fi
+    fi
+
+    # Truncate typescript
+    truncate -s 0 $HELP50
+}
+
+function _question() {
+    _alert "That was a rhetorical question. :)"
+}
+
+# Default helpers
+if ! type _helpful >/dev/null 2>&1; then
+    function _helpful() {
+
+        # Intercept accidental invocation of `yes` and `n`, which are actual programs
+        for name in n no y yes; do
+            alias $name=_question
+        done
+
+        # Output help
+        local output=$(_ansi "$1")
+        _alert "$output"
+    }
+fi
+if ! type _helpless >/dev/null 2>&1; then
+    function _helpless() { :; } # Silent
+fi
+
+export PROMPT_COMMAND=_help50
+
+# touch foo.c && touch foo && ./foo
+function _trap() {
+    if [[ "$BASH_COMMAND" =~ ^\./(.*)$ ]]; then
+        local src="${BASH_REMATCH[1]}.c"
+        local dst="${BASH_REMATCH[1]}"
+        if [[ "$src" -nt "$dst" ]]; then
+            local output=$(_ansi "It looks like \`$src\` has changed. Did you mean to run \`make $dst\` again?")
+            _alert "$output"
+        fi
+    fi
+}
+trap _trap DEBUG

opt/cs50/bin/help50

@@ -0,0 +1,94 @@
+#!/bin/bash
+
+# If root
+if [[ `id -u` -eq 0 ]]; then
+    exit 1
+fi
+
+function _disable() {
+    touch /tmp/help50.lock
+}
+
+function _is-enabled() {
+    if [[ -f /tmp/help50.lock ]]; then
+        echo disabled
+        return 1
+    else
+        echo enabled
+        return 0
+    fi
+}
+
+function _enable() {
+    rm --force /tmp/help50.lock
+}
+
+function _start() {
+
+    # If already helping
+    if [[ -n "$HELP50" ]]; then
+        return 0
+    fi
+
+    # Uniquely identify typescript using PID of parent shell to help
+    local HELP50=/tmp/help50.$PPID
+
+    # Start `script` in background, using ; instead of && for command,
+    # else if user logs out (as via ctl-d) after a non-0 command, bash exits with 127
+    set -o monitor
+    HELP50=$HELP50 script --append --command "bash --login ; exit 1" --flush --quiet --return $HELP50
+    local status=$?
+
+    # No longer helping
+    rm --force $HELP50
+
+    # If `script` was killed, in which case `exit 1` above won't execute
+    if [[ $status -ne 1 ]]; then
+
+        # Without this, prompt ends up below and to right of "Session terminated, killing shell... ...killed."
+        echo -e "\r"
+
+    # Else if `script` exited on its own, as via ctl-d or `logout`
+    else
+
+        # Kill parent shell, since user presumably wants to exit
+        kill -SIGHUP $PPID
+    fi
+}
+
+function _stop() {
+
+    # If not helping
+    if [[ -z "$HELP50" ]]; then
+        return 0
+    fi
+
+    # Kill grandparent process (i.e., `script` itself)
+    local ppid=$(ps -o ppid= -p $$) # bash --login
+    local gppid=$(ps -o ppid= -p $ppid) # sh -c
+    local ggppid=$(ps -o ppid= -p $gppid) # script
+    kill -SIGTERM $ggppid
+}
+
+# Parse argument
+case "$1" in
+    disable)
+        _disable
+        ;;
+    enable)
+        _enable
+        ;;
+    is-enabled)
+        _is-enabled
+        ;;
+    start)
+        _start
+        ;;
+    stop)
+        _stop
+        ;;
+    *)
+        echo "Usage: $0 [disable|enable|is-enabled|start|stop]"
+        exit 1
+        ;;
+esac

opt/cs50/bin/http-server

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+. /opt/cs50/lib/cli
+
 # Default options
 a="-a 0.0.0.0"
 c="-c-1"
@@ -9,22 +11,16 @@ port="-p 8080"
 options="--no-dotfiles"
 t="-t0"
 
-# Formatting
-bold=$(tput bold)
-normal=$(tput sgr0)
-
 # Check for app.py or wsgi.py
 if [[ -f app.py ]] || [[ -f wsgi.py ]]; then
-    read -p "Are you sure you want to run ${bold}http-server${normal} and not ${bold}flask${normal}? [y/N] " -r
-    if [[ ! "${REPLY,,}" =~ ^y|yes$ ]]; then
+    if ! _sure "Are you sure you want to run \`http-server\` and not \`flask\`?"; then
         exit 1
     fi
 fi
 
 # Check for path
 if [[ $# -eq 1 ]] && [[ $1 != -* ]] && [[ ! $1 =~ ^\./?$ ]]; then
-    read -p "Are you sure you want to serve ${bold}${1}${normal} and not your current directory? [y/N] " -r
-    if [[ ! "${REPLY,,}" =~ ^y|yes$ ]]; then
+    if ! _sure "Are you sure you want to serve \`${1}\` and not your current directory?"; then
         exit 1
     fi
 fi

opt/cs50/bin/make

@@ -1,23 +1,18 @@
 #!/bin/bash
 
-# Ensure no targets end with .c
-args=""
-invalid_args=0
-for arg; do
-    case "$arg" in
-        (*.c) arg=${arg%.c}; invalid_args=1;;
-    esac
-    args="$args $arg"
-done
-if [ $invalid_args -eq 1 ]; then
-    echo "Did you mean 'make$args'?"
-    exit 1
-fi
+# If a single target and not an option
+if [[ $# -eq 1 ]] && [[ "$1" != -* ]]; then
+
+    # If target ends with .c or is a directory
+    if [[ "$1" == *?.c || -d "$1" ]]; then
 
-# Run make
-if [[ -d "$1" ]]; then
-    echo "$1 is a directory"
-    exit 1
-else
-    /usr/bin/make -B -s $*
+        # Don't suppress "Nothing to be done" with --silent
+        /usr/bin/make "$1"
+
+        # Else make exits with 0
+        exit 1
+    fi
 fi
+
+# Don't echo recipes
+/usr/bin/make --always-make --silent "$@"

opt/cs50/bin/sqlite3

@@ -1,8 +1,6 @@
 #!/bin/bash
 
-# Formatting
-bold=$(tput bold)
-normal=$(tput sgr0)
+. /opt/cs50/lib/cli
 
 # If data is coming from stdin (pipe or redirection)
 if [[ -p /dev/stdin || ! -t 0 ]]; then
@@ -12,22 +10,19 @@ fi
 
 # If no command-line argument
 if [[ $# -eq 0 ]]; then
-    read -p "Are you sure you want to run ${bold}sqlite3${normal} without a command-line argument (e.g., the filename of a database)? [y/N] " -r
-    if [[ ! "${REPLY,,}" =~ ^y|yes$ ]]; then
+    if ! _sure "Are you sure you want to run \`sqlite3\` without a command-line argument (e.g., the filename of a database)?"; then
         exit 1
     fi
 
 # If one command-line argument
 elif [[ $# -eq 1 ]] && [[ ! "$1" =~ ^- ]]; then
     if [[ ! -f "$1" ]]; then
         if [[ ! "$1" =~ \.db$ ]]; then
-            read -p "Are you sure you want to create ${bold}$1${normal}? SQLite filenames usually end in ${bold}.db${normal}. [y/N] " -r
-            if [[ ! "${REPLY,,}" =~ ^y|yes$ ]]; then
+            if ! _sure "Are you sure you want to create \`$1\`? SQLite filenames usually end in \`.db\`."; then
                 exit 1
             fi
         else
-            read -p "Are you sure you want to create ${bold}$1${normal}? [y/N] " -r
-            if [[ ! "${REPLY,,}" =~ ^y|yes$ ]]; then
+            if ! _sure "Are you sure you want to create \`$1\`?"; then
                 exit 1
             fi
         fi

opt/cs50/bin/valgrind

@@ -1,12 +1,8 @@
 #!/bin/bash
 
-# Formatting
-bold=$(tput bold)
-normal=$(tput sgr0)
-
 # If run on Python program
 if [[ "$1" == "python" || "$1" == *.py ]]; then
-    echo "Afraid ${bold}valgrind${normal} does not support Python programs!"
+    echo "$(_help "Afraid \`valgrind\` does not support Python programs!")"
     exit 1
 fi