Display unrar File Attributes in Octal Format

The official unrar command-line utility does not provide a native flag to output file permissions directly in octal format (such as 0755 or 0644). When inspecting archives, unrar outputs POSIX file permissions strictly in symbolic notation (such as -rwxr-xr-x). To display these attributes in octal notation without extracting the files, you must use the technical listing command in unrar and parse its symbolic output using a shell pipeline or script.

Understanding unrar Permission Output

When listing archive contents with detailed attributes, run:

unrar lt archive.rar

The lt command instructs unrar to show technical information. Within the output, permissions appear on the Attributes line:

Attributes: -rwxr-xr-x
      Name: script.sh

Because unrar does not include an option like --octal, converting -rwxr-xr-x into 755 requires translating the standard 9-character permission mask into numerical bits.

Method 1: Using an AWK Pipeline (Recommended)

You can pipe the output of unrar lt directly into awk to calculate the octal values on the fly. This solution works out of the box on standard Linux and macOS terminal environments without writing files to disk.

Run the following command:

unrar lt archive.rar | awk '
/^[ \t]*Attributes:[ \t]*/ {
    attr = $2
    u = (substr(attr,2,1)=="r"?4:0) + (substr(attr,3,1)=="w"?2:0) + (substr(attr,4,1)=="x"?1:0)
    g = (substr(attr,5,1)=="r"?4:0) + (substr(attr,6,1)=="w"?2:0) + (substr(attr,7,1)=="x"?1:0)
    o = (substr(attr,8,1)=="r"?4:0) + (substr(attr,9,1)=="w"?2:0) + (substr(attr,10,1)=="x"?1:0)
    mode = sprintf("%d%d%d", u, g, o)
}
/^[ \t]*Name:[ \t]*/ {
    sub(/^[ \t]*Name:[ \t]*/, "")
    print mode, $0
}'

How It Works:

1. Attribute Extraction: Matches the Attributes: line and reads the 10-character string (e.g., -rw-r--r--).
2. Bit Calculation: Evaluates User (u), Group (g), and Other (o) triplets using standard binary weights (r=4, w=2, x=1).
3. Filename Association: Matches the subsequent Name: line and prints the octal representation alongside the archive path.

Method 2: Using a Python One-Liner

If you prefer Python for handling multi-byte characters or complex archive paths, run:

unrar lt archive.rar | python3 -c '
import sys, re

mode = ""
for line in sys.stdin:
    attr_match = re.search(r"Attributes:\s*([drwxstST-]{10})", line)
    if attr_match:
        p = attr_match.group(1)[1:]
        val = 0
        for char in p:
            val = (val << 1) | (1 if char in "rwxst" else 0)
        mode = oct(val)[2:].zfill(3)
    name_match = re.search(r"Name:\s*(.*)", line)
    if name_match and mode:
        print(f"{mode}  {name_match.group(1)}")
        mode = ""
'

Method 3: Parsing unrar v -c- Table Format

If you prefer standard table listings rather than technical multi-line listings, use verbose list mode:

unrar v -c- archive.rar

This prints a tabular layout where the first column contains the permissions. You can filter and translate this output using:

unrar v -c- archive.rar | awk '
/^[d-]r/ {
    attr = $1
    u = (substr(attr,2,1)=="r"?4:0) + (substr(attr,3,1)=="w"?2:0) + (substr(attr,4,1)=="x"?1:0)
    g = (substr(attr,5,1)=="r"?4:0) + (substr(attr,6,1)=="w"?2:0) + (substr(attr,7,1)=="x"?1:0)
    o = (substr(attr,8,1)=="r"?4:0) + (substr(attr,9,1)=="w"?2:0) + (substr(attr,10,1)=="x"?1:0)
    filename = $NF
    printf "%d%d%d %s\n", u, g, o, filename
}'

This produces clean, two-column output displaying the numerical octal mask alongside each target file.