Custom Greeting with STAT Fallback

When deploying a PBX, custom audio greetings are rarely ready on day one. This pattern checks whether a custom greeting file exists on disk and plays it if found, otherwise falls back to Asterisk's built-in sound files. This lets you deploy with generic greetings and drop in custom recordings later without any dialplan changes.

The Snippet

[ivr-main]
exten => s,1,Answer()
 same => n,Wait(1)
 ; Check for custom greeting in any common audio format
 same => n,Set(GREETING=/var/lib/asterisk/sounds/custom/main-greeting)
 same => n,GotoIf($[${STAT(e,${GREETING}.wav)} || ${STAT(e,${GREETING}.ulaw)} || ${STAT(e,${GREETING}.gsm)}]?play_custom)
 ;
 ; No custom greeting found - use built-in sounds
 same => n,Playback(thank-you-for-calling)
 same => n,Goto(menu)
 ;
 same => n(play_custom),Playback(${GREETING})
 same => n(menu),Background(press-1&press-2&or&press-3)
 same => n,WaitExten(5)

How It Works

STAT(e,filename) returns 1 if the file exists, 0 if it doesn't. The e flag specifically tests for existence. By checking for .wav, .ulaw, and .gsm extensions, the pattern works regardless of which audio format was uploaded.

Note that Playback() doesn't need the file extension. Asterisk automatically finds the best format match. But STAT() checks actual files on disk, so we need to include extensions.

The GREETING variable stores only the base path (no extension). This way, Playback(${GREETING}) lets Asterisk choose the optimal format for the channel's codec.

Where to Place Custom Greetings

/var/lib/asterisk/sounds/custom/
    main-greeting.wav          # Main IVR greeting
    afterhours-greeting.wav    # After-hours message
    holiday-greeting.wav       # Holiday closure message
    queue-holdmusic.wav        # Custom hold music

Create the directory if it doesn't exist:

mkdir -p /var/lib/asterisk/sounds/custom
chown asterisk:asterisk /var/lib/asterisk/sounds/custom

Recording Format

For best compatibility, record in one of these formats:

• WAV: 8000 Hz, 16-bit, mono PCM (most universal)
• ulaw: 8000 Hz mu-law (native PSTN format, smallest files)
• GSM: Compressed, good for storage-constrained systems

Convert with sox:

# Convert any audio to Asterisk-compatible WAV
sox input.mp3 -r 8000 -c 1 -e signed-integer -b 16 output.wav

# Convert to ulaw
sox input.mp3 -r 8000 -c 1 -t ul output.ulaw

Using with After-Hours

The same pattern works for after-hours greetings, where each department can have its own custom greeting:

; Subroutine: call via Gosub(sub-afterhours,s,1(sales))
[sub-afterhours]
exten => s,1,Answer()
 same => n,Wait(1)
 ; ARG1 = department name (e.g., "sales", "support")
 same => n,Set(AH_GREETING=/var/lib/asterisk/sounds/custom/afterhours-${ARG1})
 same => n,GotoIf($[${STAT(e,${AH_GREETING}.wav)} || ${STAT(e,${AH_GREETING}.ulaw)}]?play_custom)
 ; Generic fallback
 same => n,Playback(thank-you-for-calling)
 same => n,Goto(continue)
 same => n(play_custom),Playback(${AH_GREETING})
 same => n(continue),Return()

; Example: route to after-hours with department name
[incoming-sales]
exten => s,1,Gosub(sub-afterhours,s,1(sales))
 same => n,Hangup()

Call via Gosub() so that ${ARG1} is populated with the department name. Dropping afterhours-sales.wav into the custom sounds directory instantly gives the sales department a personalized greeting.