(notonline)-->
--
-- demo\rosetta\Simple_db.exw
-- ==========================
--
without js -- (file i/o, gets(0), getenv)
include timedate.e
constant filename = getenv(iff(platform()=WINDOWS?"APPDATA":"HOME"))&"/simple_db.csv"
procedure add(sequence cmd)
if length(cmd)=0
or length(cmd)>2 then
printf(1,"usage: add name [cat]\n")
else
string name = cmd[1],
cat = iff(length(cmd)=2?cmd[2]:"none")
datestr = format_timedate(date(),"YYYY/MM/DD h:mmpm")
integer fn = open(filename,"a")
printf(fn,"%s,%s,%s\n",{name,cat,datestr})
close(fn)
end if
end procedure
procedure last(sequence cmd)
integer fn = open(filename,"r")
if fn=-1 then
puts(1,"file not found\n")
return
end if
integer lc = length(cmd)
string last = iff(lc?"<no entries for that category>\n":"<empty>\n")
while 1 do
object line = gets(fn)
if atom(line) then exit end if
if lc=0 or split(line,',')[2]=cmd[1] then
last = line
end if
end while
puts(1,last)
close(fn)
end procedure
sequence dates
function by_date(integer d1, integer d2)
return compare(dates[d1],dates[d2])
end function
procedure sort_by_date()
-- (simple_db.csv should be edited manually to prove the date sort works)
integer fn = open(filename,"r")
if fn=-1 then
puts(1,"file not found\n")
return
end if
sequence lines = {}
dates = {}
while 1 do
object line = gets(fn)
if atom(line) then exit end if
lines = append(lines,line)
dates = append(dates,split(line,',')[3])
end while
close(fn)
sequence tags = custom_sort(by_date,tagset(length(lines)))
for i=1 to length(tags) do
puts(1,lines[tags[i]])
end for
end procedure
procedure process(sequence cmd)
switch cmd[1] do
case "add": add(cmd[2..$])
case "last": last(cmd[2..$])
case "sort": sort_by_date()
default: printf(1,"unknown command: %s\n",{cmd[1]})
end switch
end procedure
constant helptext = """
p demo\rosetta\Simple_db -- interactive mode, commands as below
p demo\rosetta\Simple_db add name [cat] -- add entry
p demo\rosetta\Simple_db last [cat] -- show last entry [in specified category]
p demo\rosetta\Simple_db sort -- show full list sorted by date
"""
sequence cl = command_line()
if length(cl)<3 then
-- interactive mode
puts(1,helptext)
while 1 do
puts(1,">")
object line = trim(gets(0))
if atom(line) or length(line)=0 then exit end if
puts(1,"\n")
process(split(line))
end while
else
process(cl[3..$])
end if