Test Command (t)

The t (test) command verifies the integrity of archives by checking checksums and attempting decompression without writing files to disk.

Syntax

7z t [<switches>...] <archive_name> [<file_names>...] [@listfile]

Description

The test command:

Verifies archive structure and headers
Checks CRC checksums for all files
Tests decompression without extracting to disk
Detects corruption, errors, or incomplete archives
Works with encrypted archives (requires password)
Can test specific files or entire archives

Common Options

string

required

Name of the archive to test. Auto-detects archive type.

string

Specific files or patterns to test. If omitted, tests all files.Example: *.txt or documents/report.pdf

string

Provide password for encrypted archives.Example: -pMyPassword or -p (prompts)

flag

Recurse subdirectories (enabled by default).

string

Exclude files from testing by pattern.Example: -x!*.tmp

string

Include only files matching pattern.Example: -i!*.txt

string

Specify archive type (usually auto-detected).Example: -t7z

string

Set hash function for testing: CRC32, CRC64, SHA256, SHA1, etc.Example: -scrcSHA256

flag

Disable progress indicator.

number

Set output log level (0=quiet, 1=errors, 2=errors+warnings, 3=verbose).

Examples

Test entire archive

7z t archive.7z

Output (success):

7-Zip 23.01 (x64) : Copyright (c) 1999-2023 Igor Pavlov : 2023-06-20

Scanning the drive for archives:
1 file, 23456 bytes (23 KiB)

Testing archive: archive.7z

--
Path = archive.7z
Type = 7z
Physical Size = 23456
Headers Size = 234
Method = LZMA2:24
Solid = -
Blocks = 1

Everything is Ok

Folders: 3
Files: 12
Size:       45678
Compressed: 23456

Output (failure):

Testing archive: corrupted.7z

--
Path = corrupted.7z
Type = 7z

ERROR: Data Error : document.txt

Sub items Errors: 1

Archives with Errors: 1

Test password-protected archive

7z t -p archive.7z

Prompts:

Enter password (will not be echoed):

Or provide password directly:

7z t -pMyPassword archive.7z

Test specific files

7z t archive.7z readme.txt license.txt

Test files by pattern

7z t archive.7z *.txt -r

Test excluding certain files

7z t archive.7z -x!*.tmp -x!*.bak

Test quietly (exit code only)

7z t archive.7z -bd -bb0
echo $?  # 0 = success, non-zero = failure

Test with verbose output

7z t archive.7z -bb3

Test multi-volume archive

7z t archive.7z.001

Automatically tests all volumes.

Test multiple archives

7z t *.7z

Test with SHA256 checksums

7z t archive.7z -scrcSHA256

Exit Codes

The test command returns exit codes that indicate test results:

Code	Meaning	Description
0	Success	Archive is OK, no errors
1	Warning	Non-fatal errors (some files may be OK)
2	Fatal Error	Archive is corrupted or unreadable
7	Command Line Error	Invalid command syntax
8	Not Enough Memory	Insufficient memory to test
255	User Stopped	User interrupted the process

Testing Strategies

Quick Test Script

if 7z t archive.7z -bd > /dev/null 2>&1; then
    echo "Archive is OK"
else
    echo "Archive is corrupted (exit code: $?)"
fi

Test All Archives in Directory

for archive in *.7z; do
    echo "Testing $archive..."
    if 7z t "$archive" -bd -bb0; then
        echo "✓ $archive is OK"
    else
        echo "✗ $archive is CORRUPTED"
    fi
done

Test and Log Results

7z t archive.7z > test_results.log 2>&1
if [ $? -eq 0 ]; then
    echo "Test passed" >> test_results.log
else
    echo "Test failed" >> test_results.log
fi

Test Before Extraction

7z t archive.7z && 7z x archive.7z -o./output

Only extracts if test succeeds.

Advanced Examples

Test with progress to file

7z t archive.7z -bsp1 2> progress.log

Test and capture errors

7z t archive.7z 2>&1 | grep -i error

Parallel testing of multiple archives

find . -name "*.7z" -print0 | xargs -0 -P 4 -I {} sh -c '7z t "{}" -bd && echo "{}" OK'

Test archive chain

for i in {1..10}; do
    if ! 7z t archive.7z.00$i -bd -bb0; then
        echo "Volume $i is corrupted"
        break
    fi
done

Understanding Test Results

Successful Test

Everything is Ok

Folders: 3
Files: 12
Size:       45678
Compressed: 23456

All files passed CRC check and decompression.

CRC Error

ERROR: CRC Failed : document.txt

File’s checksum doesn’t match. File is corrupted.

Data Error

ERROR: Data Error : archive.txt

Decompression failed. Archive data is corrupted.

Headers Error

ERROR: Headers Error

Archive structure is damaged.

Wrong Password

ERROR: Wrong password : encrypted.txt

Incorrect password provided for encrypted archive.

Unsupported Method

ERROR: Unsupported Method

Archive uses compression method not supported by this 7-Zip build.

Testing Different Archive Types

Test ZIP archive

7z t archive.zip

Test RAR archive

7z t archive.rar

Test TAR.GZ archive

7z t archive.tar.gz

Test ISO image

7z t image.iso

Test self-extracting archive

7z t archive.exe

Test split archive

7z t archive.zip.001

Automated Testing

Cron Job for Regular Testing

#!/bin/bash
# /etc/cron.daily/test-archives

ARCHIVE_DIR="/backup/archives"
LOG_FILE="/var/log/archive-tests.log"

date >> "$LOG_FILE"
find "$ARCHIVE_DIR" -name "*.7z" | while read archive; do
    if 7z t "$archive" -bd -bb0 >> "$LOG_FILE" 2>&1; then
        echo "OK: $archive" >> "$LOG_FILE"
    else
        echo "FAIL: $archive" >> "$LOG_FILE"
        # Send alert
        echo "Archive test failed: $archive" | mail -s "Archive Test Failure" admin@example.com
    fi
done

Test with Timeout

timeout 300 7z t large_archive.7z
if [ $? -eq 124 ]; then
    echo "Test timed out after 5 minutes"
fi

Test and Compare Checksums

# Test with CRC32
7z t archive.7z -scrcCRC32 > /tmp/crc32.txt
# Test with SHA256
7z t archive.7z -scrcSHA256 > /tmp/sha256.txt
# Compare results
diff /tmp/crc32.txt /tmp/sha256.txt

The test command reads and decompresses files but does not write them to disk, making it safe to run on any archive without worrying about disk space or file conflicts.

A successful test does not guarantee that files will extract properly in all cases. It only verifies CRC checksums and basic decompression. Physical media errors during extraction could still occur.

Always test archives after creating them, especially before deleting source files:

7z a archive.7z files/ && 7z t archive.7z && rm -rf files/

Performance Considerations

Testing is faster than extraction (no disk writes)
Solid archives must decompress sequentially (slower)
Multi-volume archives test faster with all volumes present
Encrypted archives require full decompression (slower)
Password-protected headers require password even for testing

Extract Command (x, e) - Extract files from archive
List Command (l) - View archive contents
Hash Command (h) - Calculate file checksums

​Syntax

​Description

​Common Options

​Examples

​Test entire archive

​Test password-protected archive

​Test specific files

​Test files by pattern

​Test excluding certain files

​Test quietly (exit code only)

​Test with verbose output

​Test multi-volume archive

​Test multiple archives

​Test with SHA256 checksums

​Exit Codes

​Testing Strategies

​Quick Test Script

​Test All Archives in Directory

​Test and Log Results

​Test Before Extraction

​Advanced Examples

​Test with progress to file

​Test and capture errors

​Parallel testing of multiple archives

​Test archive chain

​Understanding Test Results

​Successful Test

​CRC Error

​Data Error

​Headers Error

​Wrong Password

​Unsupported Method

​Testing Different Archive Types

​Test ZIP archive

​Test RAR archive

​Test TAR.GZ archive

​Test ISO image

​Test self-extracting archive

​Test split archive

​Automated Testing

​Cron Job for Regular Testing

​Test with Timeout

​Test and Compare Checksums

​Performance Considerations

​Related Commands

Syntax

Description

Common Options

Examples

Test entire archive

Test password-protected archive

Test specific files

Test files by pattern

Test excluding certain files

Test quietly (exit code only)

Test with verbose output

Test multi-volume archive

Test multiple archives

Test with SHA256 checksums

Exit Codes

Testing Strategies

Quick Test Script

Test All Archives in Directory

Test and Log Results

Test Before Extraction

Advanced Examples

Test with progress to file

Test and capture errors

Parallel testing of multiple archives

Test archive chain

Understanding Test Results

Successful Test

CRC Error

Data Error

Headers Error

Wrong Password

Unsupported Method

Testing Different Archive Types

Test ZIP archive

Test RAR archive

Test TAR.GZ archive

Test ISO image

Test self-extracting archive

Test split archive

Automated Testing

Cron Job for Regular Testing

Test with Timeout

Test and Compare Checksums

Performance Considerations

Related Commands