| #1. PLAY NU MPV |
| Published: 2025-09-27 [Sat] 02:22, by |
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https://x0.at/30jh.png #!/bin/bash # ┏━┓╻ ┏━┓╻ ╻┏┓╻╻ ╻┏┳┓┏━┓╻ ╻ USAGE: playnumpv <days> # ┣━┛┃ ┣━┫┗┳┛┃┗┫┃ ┃┃┃┃┣━┛┃┏┛ (where days = number of days to # ╹ ┗━╸╹ ╹ ╹ ╹ ╹┗━┛╹ ╹╹ ┗┛ search back for newer media files) # Check if argument is provided if [ -z "$1" ] || [[ ! "$1" =~ ^[0-9]+$ ]]; then echo "Usage: $0 <days>" exit 1 fi # Create a temporary playlist file in a safe location playlist=$(mktemp) || { echo "Failed to create temporary file"; exit 1; } # Set trap to clean up temporary file on exit trap 'rm -f "$playlist"' EXIT # Get absolute path of the playlist to exclude it from search abs_playlist=$(realpath "$playlist") # Find all media files modified in the last $1 days and add them to the playlist # Using absolute paths to avoid issues with relative paths find "$PWD" -type f -regextype posix-extended -regex '.*\.(mp3|flac|opus|ogg|m4a|wav|nsf|mod|xm)' \ -mtime -"${1}" ! -path "$abs_playlist" -print0 | \ sort -z | \ tr '\0' '\n' > "$playlist" # Check if any files were found if [ ! -s "$playlist" ]; then echo "No files found newer than ${1} days."; exit 0 fi # Count the number of files in the playlist file_count=$(wc -l < "$playlist") echo "Found $file_count files to play." # Play playlist with mpv using unbuffer to maintain terminal connection # and process substitution to capture output without breaking stdin unbuffer -p mpv --shuffle --term-osd=auto --osd-level=2 --no-audio-display \ --playlist="$playlist" 2>&1 > >(grep -E "Playing") < /dev/tty |
| #2. explanation console stdin, stdout, redirection |
| Published: 2025-09-27 [Sat] 03:37, by |
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#!/bin/bash # ┏━┓╻ ┏━┓╻ ╻┏┓╻╻ ╻┏┳┓┏━┓╻ ╻ USAGE: playnumpv <days> # ┣━┛┃ ┣━┫┗┳┛┃┗┫┃ ┃┃┃┃┣━┛┃┏┛ (where days = number of days to # ╹ ┗━╸╹ ╹ ╹ ╹ ╹┗━┛╹ ╹╹ ┗┛ search back for newer media files) # Check if argument is provided if [ -z "$1" ] || [[ ! "$1" =~ ^[0-9]+$ ]]; then echo "Usage: $0 <days>" exit 1 fi # Create a temporary playlist file in a safe location playlist=$(mktemp) || { echo "Failed to create temporary file"; exit 1; } # Set trap to clean up temporary file on exit trap 'rm -f "$playlist"' EXIT # Get absolute path of the playlist to exclude it from search abs_playlist=$(realpath "$playlist") # Find all media files modified in the last $1 days and add them to the playlist # Using absolute paths to avoid issues with relative paths find "$PWD" -type f -regextype posix-extended -regex '.*\.(mp3|flac|opus|ogg|m4a|wav|nsf|mod|xm)' \ -mtime -"${1}" ! -path "$abs_playlist" -print0 | \ sort -z | \ tr '\0' '\n' > "$playlist" # Check if any files were found if [ ! -s "$playlist" ]; then echo "No files found newer than ${1} days." exit 0 fi # Count the number of files in the playlist file_count=$(wc -l < "$playlist") echo "Found $file_count files to play." # Play the playlist with mpv, using unbuffer to maintain terminal connection # and process substitution to capture output without breaking stdin unbuffer -p mpv --shuffle --term-osd=auto --osd-level=2 --no-audio-display \ --playlist="$playlist" 2>&1 > >(grep -E "Playing") < /dev/tty # Multi-line comment explaining the redirection technique: : <<'EOF' EXPLANATION OF THE REDIRECTION TECHNIQUE: The command uses several advanced shell features to maintain keyboard control while filtering output: 1. `unbuffer -p`: - Creates a pseudo-terminal for mpv - Ensures mpv maintains interactive behavior including keyboard input handling 2. `2>&1`: - Redirects stderr to stdout - Combines both output streams 3. `> >(grep -E "Playing")`: - Uses process substitution (the `>(...)` syntax) - Creates a temporary file descriptor connected to grep - Sends mpv's output to grep without breaking terminal connection - Unlike a regular pipe, this doesn't disrupt keyboard input 4. `< /dev/tty`: - Explicitly redirects stdin to the terminal device - Ensures mpv gets keyboard input directly from the terminal - This is critical for maintaining keyboard control WHY THIS WORKS WHEN REGULAR PIPES FAIL: Regular pipes (mpv | grep) break keyboard input because: - The shell puts commands in separate process groups - mpv detects its output is going to a pipe and may change behavior - Terminal control gets disrupted Our solution works because: - unbuffer maintains the terminal connection - Process substitution doesn't break the terminal connection like a pipe - Explicit terminal input redirection ensures keyboard control - The combination preserves mpv's interactive capabilities DATA FLOW: Keyboard Input → /dev/tty → mpv (via unbuffer) → Process Substitution → grep → Terminal EOF |