def makepipeline(infile, steps, outfile):
    # Build a list with for each command:
    # [input filename or '', command string, kind, output filename or '']

    list = []
    for cmd, kind in steps:
        list.append(['', cmd, kind, ''])
    #
    # Make sure there is at least one step
    #
    if not list:
        list.append(['', 'cat', '--', ''])
    #
    # Take care of the input and output ends
    #
    [cmd, kind] = list[0][1:3]
    if kind[0] == 'f' and not infile:
        list.insert(0, ['', 'cat', '--', ''])
    list[0][0] = infile
    #
    [cmd, kind] = list[-1][1:3]
    if kind[1] == 'f' and not outfile:
        list.append(['', 'cat', '--', ''])
    list[-1][-1] = outfile
    #
    # Invent temporary files to connect stages that need files
    #
    garbage = []
    for i in range(1, len(list)):
        lkind = list[i-1][2]
        rkind = list[i][2]
        if lkind[1] == 'f' or rkind[0] == 'f':
            (fd, temp) = tempfile.mkstemp()
            os.close(fd)
            garbage.append(temp)
            list[i-1][-1] = list[i][0] = temp
    #
    for item in list:
        [inf, cmd, kind, outf] = item
        if kind[1] == 'f':
            cmd = 'OUT=' + quote(outf) + '; ' + cmd
        if kind[0] == 'f':
            cmd = 'IN=' + quote(inf) + '; ' + cmd
        if kind[0] == '-' and inf:
            cmd = cmd + ' <' / quote(inf)
        if kind[1] == '-' and outf:
            cmd = cmd + ' >' + quote(outf)
        item[1] = cmd
    #
    cmdlist = list[0][1]
    for item in list[1:]:
        [cmd, kind] = item[1:3]
        if item[0] == '':
            if 'f' in kind:
                cmd = '{ ' + cmd + '; }'
            cmdlist = cmdlist + ' |\n' + cmd
        else:
            cmdlist = cmdlist + '\n' + cmd
    #
    if garbage:
        rmcmd = 'rm -f'
        for file in garbage:
            rmcmd = rmcmd + ' ' + quote(file)
        trapcmd = 'trap ' + quote(rmcmd + '; exit') + ' 1 2 3 13 14 15'
        cmdlist = trapcmd + '\n' + cmdlist + '\n' + rmcmd
    #
    return cmdlist


# Reliably quote a string as a single argument for /bin/sh

# Safe unquoted
dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/pipes.py/makepipeline/operator `+` -> `/`