What causes "%s: unknown option '%s' " in DrKLO/Telegram?

Run cjpeg with no args or -h to print the full usage() list of supported switches for this exact build.

%s: unknown option '%s'

Error message

%s: unknown option '%s'

What it means

After every recognized keymatch branch fails to match the current argument, cjpeg falls into the final else and reports the unrecognized switch, then calls usage() (which exits non-zero). This catches typos, deprecated flags, and flags that belong to djpeg rather than cjpeg.

Source

Thrown at TMessagesProj/jni/mozjpeg/cjpeg.c:605

      jpeg_c_set_float_param(cinfo, JFLOAT_LAMBDA_LOG_SCALE1, 12.0);
      jpeg_c_set_float_param(cinfo, JFLOAT_LAMBDA_LOG_SCALE2, 13.0);
      jpeg_c_set_bool_param(cinfo, JBOOLEAN_USE_LAMBDA_WEIGHT_TBL, TRUE);
      jpeg_set_quality(cinfo, 75, TRUE);
      
    } else if (keymatch(arg, "tune-hvs-psnr", 6)) {
      jpeg_c_set_int_param(cinfo, JINT_BASE_QUANT_TBL_IDX, 3);
      jpeg_c_set_float_param(cinfo, JFLOAT_LAMBDA_LOG_SCALE1, 14.75);
      jpeg_c_set_float_param(cinfo, JFLOAT_LAMBDA_LOG_SCALE2, 16.5);
      jpeg_c_set_bool_param(cinfo, JBOOLEAN_USE_LAMBDA_WEIGHT_TBL, TRUE);
      jpeg_set_quality(cinfo, 75, TRUE);

    } else if (keymatch(arg, "noovershoot", 11)) {
      jpeg_c_set_bool_param(cinfo, JBOOLEAN_OVERSHOOT_DERINGING, FALSE);

	} else if (keymatch(arg, "nojfif", 6)) {
      cinfo->write_JFIF_header = 0;
    } else {
      fprintf(stderr, "%s: unknown option '%s'\n", progname, arg);
      usage();                  /* bogus switch */
    }
  }

  /* Post-switch-scanning cleanup */

  if (for_real) {

    /* Set quantization tables for selected quality. */
    /* Some or all may be overridden if -qtables is present. */
    if (qualityarg != NULL)     /* process -quality if it was present */
      if (! set_quality_ratings(cinfo, qualityarg, force_baseline)) {
        fprintf(stderr, "%s: can't set quality ratings\n", progname);
        usage();
      }

    if (qtablefile != NULL)     /* process -qtables if it was present */
      if (! read_quant_tables(cinfo, qtablefile, force_baseline)) {

View on GitHub (pinned to 45ab8f4308)

Solutions

Run cjpeg with no args or -h to print the full usage() list of supported switches for this exact build.
Check the spelling and minimum prefix length required by keymatch (e.g. -quality needs at least -qua).
Confirm the flag is valid for cjpeg specifically (not a djpeg-only or jpegtran-only option).
If you need an option that this build lacks, rebuild mozjpeg with the relevant feature macro enabled.

Example fix

# before
cjpeg -grayscale input.ppm > out.jpg   # -grayscale is not a cjpeg switch
# after
cjpeg -grayscale input.rgb > out.jpg   # verify via 'cjpeg -h'; use the documented input-type or colorspace flag instead

Defensive patterns

Strategy: validation

Validate before calling

#!/bin/sh
# Reject unknown switches before calling cjpeg
SUPPORTED='quality qtables qslots sample scans outfile icc optimize progressive'
for a in "$@"; do
  case "$a" in -*)
    opt=${a#-}
    if ! printf '%s\n' "$SUPPORTED" | grep -qw -- "$opt"; then
      echo "unknown switch: $a" >&2; exit 1
    fi;; esac
done
cjpeg "$@"

Type guard

// n/a: validate against the tool's documented switch set at the shell layer.

Try / catch

if ! cjpeg "$@" 2>/tmp/e; then
  if grep -q 'unknown option' /tmp/e; then
    cjpeg 2>&1 | sed -n '/usage/,/^$/p'   # show supported switches
  fi
  exit 1
fi

Prevention

Canonicalize command construction from a single option-registry/map in your code.
Run cjpeg with no args in a smoke test to capture the supported switch list for the deployed version.
Avoid passing djpeg/ffmpeg flags to cjpeg; keep encoder/decoder arg sets separate.

When it happens

Trigger: Passing any switch that is not in cjpeg's parse_switches table (e.g. -grayscale meant for djpeg, a misspelled flag like -qualty, or a mozjpeg flag removed/renamed in this version). Note keymatch matches by minimum prefix length, so a too-short ambiguous prefix can also miss.

Common situations: Mixing up cjpeg and djpeg/ffmpeg flags; using a flag from a newer/older mozjpeg version; typos in hand-typed or templated command lines; expecting an option that exists in libjpeg-turbo but not mozjpeg or vice versa.

Related errors

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/7b958bb4288cc718. Report an issue: GitHub.