# 1. read CSV to hledger journal format
 rm -rf t.rules$$; printf 'date-field 0\ndate-format %%d/%%Y/%%m\ndescription-field 1\namount-field 2\ncurrency $\nbase-account assets:myacct\n' >t.rules$$; echo '10/2009/09,Flubber Co,50' | hledgerdev -f- print --rules-file t.rules$$; rm -rf t.rules$$
>>>
2009/09/10 Flubber Co
    income:unknown          $-50
    assets:myacct            $50

>>>2 /using conversion rules file.*t.rules/
>>>=0

# 2. reading CSV with in-field and out-field
 printf 'base-account Assets:MyAccount\ndate-field 0\ndate-format %%d/%%Y/%%m\ndescription-field 1\nin-field 2\nout-field 3\ncurrency $\n' >$$.rules ; hledgerdev -f- print --rules-file $$.rules; rm -rf $$.rules
<<<
10/2009/09,Flubber Co,50,
11/2009/09,Flubber Co,,50
>>>
2009/09/10 Flubber Co
    income:unknown            $-50
    Assets:MyAccount           $50

2009/09/11 Flubber Co
    expenses:unknown           $50
    Assets:MyAccount          $-50

>>>2 /using conversion rules file.*[0-9]+\.rules/
>>>=0

# 3. report rules parse error
# rm -rf t.rules$$; printf 'date-fiel 0\ndate-format %%d/%%Y/%%m\ndescription-field 1\namount-field 2\ncurrency $\nbase-account assets:myacct\n' >t.rules$$; echo '10/2009/09,Flubber Co,50' | hledgerdev convert --rules-file t.rules$$; rm -rf t.rules$$
# >>>
# 2009/09/10 Flubber Co
#     income:unknown          $-50
#     assets:myacct            $50

# >>>2 /using conversion rules file.*t.rules/
# >>>=0