SHASUM(1p)

📦
version 6.04 · 6 versions
, in ubuntu stonking

💖 SHASUM(1p) — the perl one, bestie 💖

okay so this is shasum, a little Perl situation that lives in the User Contributed Perl Documentation zone, and she is literally here to print or check SHA checksums. that's it. that's the whole job. and she does it beautifully. 🫶

✨ NAME ✨

shasum — Print or Check SHA Checksums 🎀

🌸 SYNOPSIS 🌸

Usage: shasum [OPTION]... [FILE]...
Print or check SHA checksums.
With no FILE, or when FILE is -, read standard input.

  -a, --algorithm   1 (default), 224, 256, 384, 512, 512224, 512256
  -b, --binary      read in binary mode
  -c, --check       read SHA sums from the FILEs and check them
      --tag         create a BSD-style checksum
  -t, --text        read in text mode (default)
  -U, --UNIVERSAL   read in Universal Newlines mode
                        produces same digest on Windows/Unix/Mac
  -0, --01          read in BITS mode
                        ASCII '0' interpreted as 0-bit,
                        ASCII '1' interpreted as 1-bit,
                        all other characters ignored

The following five options are useful only when verifying checksums:
      --ignore-missing  don't fail or report status for missing files
  -q, --quiet           don't print OK for each successfully verified file
  -s, --status          don't output anything, status code shows success
      --strict          exit non-zero for improperly formatted checksum lines
  -w, --warn            warn about improperly formatted checksum lines

  -h, --help        display this help and exit
  -v, --version     output version information and exit

When verifying SHA-512/224 or SHA-512/256 checksums, indicate the
algorithm explicitly using the -a option, e.g.

  shasum -a 512224 -c checksumfile

The sums are computed as described in FIPS PUB 180-4.  When checking,
the input should be a former output of this program.  The default
mode is to print a line with checksum, a character indicating type
(`*' for binary, ` ' for text, `U' for UNIVERSAL, `^' for BITS),
and name for each FILE.  The line starts with a `\' character if the
FILE name contains either newlines or backslashes, which are then
replaced by the two-character sequences `\n' and `\\' respectively.

Report shasum bugs to mshelor@cpan.org

so yeah that's the whole vibe in one shot. 💅 no FILE given? or FILE is literally just -? then she reads standard input, no questions asked, iconic behaviour fr fr.

🦋 DESCRIPTION 🦋

running shasum is often the quickest way to compute SHA message digests — like, genuinely the fastest glow-up for your data. you just feed data to the script through files or standard input, and then you collect the results from standard output. that's the whole loop. you in, digest out. ✨

wanna see her compute digests for typical inputs like the NIST test vector "abc"? say less:

perl -e "print qq(abc)" | shasum

and if you want to use SHA-256 instead of the default SHA-1, you literally just say:

perl -e "print qq(abc)" | shasum -a 256

since shasum mimics the behavior of the combined GNU sha1sum, sha224sum, sha256sum, sha384sum, and sha512sum programs, you can install this script as a convenient drop-in replacement. no cap, she fits right in. 👑

and unlike the GNU programs, shasum encompasses the full SHA standard by allowing partial-byte inputs. that's the main character move right there. it's accomplished through the BITS option (-0). so for example, this computes the SHA-224 digest of the 7-bit message 0001100:

perl -e "print qq(0001100)" | shasum -0 -a 224

ate. 💅

🌈 OPTIONS 🌈

okay bestie, here's the menu, and we are not skipping a single one:

  • -a, --algorithm — picks your algorithm: 1 (that's the default, hi), 224, 256, 384, 512, 512224, 512256.
  • -b, --binary — read in binary mode.
  • -c, --check — read SHA sums from the FILEs and check them.
  • --tag — create a BSD-style checksum.
  • -t, --text — read in text mode (this one's the default).
  • -U, --UNIVERSAL — read in Universal Newlines mode, which produces the same digest on Windows/Unix/Mac. cross-platform queen 🧚
  • -0, --01 — read in BITS mode. ASCII '0' is interpreted as a 0-bit, ASCII '1' as a 1-bit, and all other characters are ignored.

so these next five options are useful only when verifying checksums — very specialist, very demure:

  • --ignore-missing — don't fail or report status for missing files.
  • -q, --quiet — don't print OK for each successfully verified file.
  • -s, --status — don't output anything, status code shows success.
  • --strict — exit non-zero for improperly formatted checksum lines.
  • -w, --warn — warn about improperly formatted checksum lines.

and the two little helpers, always there for you:

  • -h, --help — display this help and exit.
  • -v, --version — output version information and exit.

💜 the SHA-512/224 & SHA-512/256 thing (iykyk)

when verifying SHA-512/224 or SHA-512/256 checksums, you must indicate the algorithm explicitly using the -a option, like:

shasum -a 512224 -c checksumfile

no guessing, bestie. say it with your chest. 💖

🫶 how the output actually looks

the sums are computed as described in FIPS PUB 180-4. when checking, the input should be a former output of this program.

the default mode prints a line with:

  1. the checksum
  2. a character indicating type — `*' for binary, ` ' for text, `U' for UNIVERSAL, `^' for BITS
  3. the name for each FILE

and okay, important detail: the line starts with a `\' character if the FILE name contains either newlines or backslashes, which are then replaced by the two-character sequences `\n' and `\\' respectively. so if your filenames are chaotic, she handles it. 🎀

found a bug? Report shasum bugs to mshelor@cpan.org — she wants to know, respectfully. 🙈

👑 AUTHOR 👑

Copyright (C) 2003-2023 Mark Shelor <mshelor@cpan.org>.

⭐ SEE ALSO ⭐

shasum is implemented using the Perl module Digest::SHA.

okay that's the whole page, you're so welcome. 💖 this was documented with perl v5.42.3, dated 2026-08-19, and officially filed under SHASUM(1p). go check some checksums, bestie, you got this. ✨🦋💅

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