Bash - replace string inside all files in directory -

i have 31 .ctl files in directory, looks this:

load data characterset al32utf8   infile '../dane/kontakty_biura_wyborcze.csv' "str '\n'" append table odi_puw_osoby2 fields terminated ';' optionally enclosed '"' , '"' trailing nullcols            ( lp char(4000),              wojewodztwo char(4000),              powiat char(4000),              gmina char(4000),              nazwa_instytucji char(4000),              kod char(4000),              miejscowosc char(4000),              adres char(4000),              nazwisko_i_imie char(4000),              funkcja char(4000),              tel_sluzb_stacjon_1 char(4000),              tel_sluzb_stacjon_2 char(4000),              tel_sluzb_stacjon_3 char(4000),              tel_sluzb_kom_1 char(4000),              tel_sluzb_kom_2 char(4000),              fax_sluzb_1 char(4000),              fax_sluzb_2 char(4000),              email_sluzb_1 char(4000),              email_sluzb_2 char(4000),              www char(4000),              typ constant "biura wyborcze.",              odi_sesja_id constant "20130717144702"              odi_status constant "0",              imie expression     "pg_odi_utils.zwroc_imiona(pg_odi_utils.usun_przyrostki(:nazwisko_i_imie),0)",              nazwisko expression "pg_odi_utils.zwroc_nazwisko(pg_odi_utils.usun_przyrostki(:nazwisko_i_imie),0)"        ) 

there 31 files this. need replace value in line:

odi_sesja_id constant '20130717144702' 

to new timestamp, same files. current timestamp not known (i mean value exists in file currently, in case '20130717144702').

so need (for each file found in directory):

• find line starting odi_sesja_id
• replace value after 'odi_sesja_id constant ' new one
• the rest lines in file should stay untouched

what best way using bash? should use sed or similar tools? how?

something like:

sed 's/\(^[ \t]\+odi_sesja_id\ constant\).*/\1 \"newtimestamp\"/' tmp 

should work.

group string retained, adding placeholder (\1) in replacement string. replace newtimestamp whatever value prefer, of course.