7zl.bat

@echo off

set "sevenz_path=C:\Program Files\7-Zip\7z.exe"
set temp_file=%temp%\7zl_output.txt

set is_found_compressed_line=0
set is_found_file_line=0
set garbage_count=

"%sevenz_path%" l "%~1" > "%temp_file%"

for /f "tokens=* delims=," %%a in (%temp_file%) do call :process_file "%%a"
pause > nul

goto :eof

:process_file
set current_line=%1

set spaceless_line=%current_line: =-%
set spaceless_line=%spaceless_line:"=%

set sanitized_line=%current_line:"=_%
set nameless_string=%sanitized_line:Name_=%

:start_strip_right_name
if not "%nameless_string:~-1%" == " " goto :end_strip_right_name
set nameless_string=%nameless_string:~0,-1%
goto :start_strip_right_name
:end_strip_right_name

if "%sanitized_line:~-5%" == "Name_" (
    if %is_found_compressed_line% equ 0 (
        set is_found_compressed_line=1
        call :strLen nameless_string garbage_count
    )
)

set /a "new_garbage_count=%garbage_count%+2"

if "%spaceless_line:~0,10%" == "----------" (
    if "%spaceless_line:~-10%" == "----------" (
        set /a "is_found_file_line=%is_found_file_line%+1"
        goto :eof
    )
)

if %is_found_file_line% equ 1 (
    if not "%sanitized_line:....A=%" == "%sanitized_line%" (
        setlocal enableDelayedExpansion
        echo !sanitized_line:~%new_garbage_count%,-1!
        endlocal
    )
)

goto :eof

rem http://stackoverflow.com/a/13924161
:strLen  strVar  [rtnVar]
setlocal disableDelayedExpansion
set len=0
if defined %~1 for /f "delims=:" %%N in (
  '"(cmd /v:on /c echo(!%~1!&echo()|findstr /o ^^"'
) do set /a "len=%%N-3"
endlocal & if "%~2" neq "" (set %~2=%len%) else echo %len%

7zl.sh

#!/bin/bash

if [[ -f "$1" ]]; then
    zip_output=$(7z l "$1")
    
    # cut off at the text Compressed
    cutoff_len=$(grep -oP "^\s+Date.+?Compressed" <<< "$zip_output")
    cutoff_len=${#cutoff_len}
    
    # but cut is one-indexed
    cutoff_len=$((cutoff_len+1))
    
    # grep only files
    # then cut by the cut off length
    # then trim the leading space and unix-ify path
    zip_output=$(echo "$zip_output" | grep "\.\.\.\.A" | cut -c "$cutoff_len-" | sed -e 's/^[[:space:]]*//' -e 's/\\/\//g')
    
    echo "$zip_output"
else
    echo "Zip path not found"
fi