having problem with new program I have been working on

[DARKNIGHT]

 hey Guys,

I am working on a new program,but have a problem with Error trapping.

if the line in question is in place, it traps the errors just fine,but it also wont allow the user to enter a file name to open or create one.

this program Allows a user to easily open or create a Data File.

you can  Enter '?' or 'Ins' for help or instructions at the prompt near the bottom of the screen.

if the file name entered, does not already exist, the program will prompt with 'File Name; does not exist, Create it? <y/n>.

Important: to set up the program, enter the file name,"dummy" at the prompt at the bottom of screen. and select ' y'  to create it.

this will create the file that lists all the saved recs

and besides  the one problem, it should be good to go

just don't use any commas in your text. it causes the text to skip to next line.

the problem line resides in the [Start] Sub, and is remed out, and has an asterisk an comment to this effect.

I would like to be able to trap option Errors, but still allow a user to enter a file name to load,or create one.

I am almost done with the program, just this one problem is stopping me.

any help would be appreciated. Thanks Guys!

Here is the code:

[Start]' * Get User Command Input

locate 3,28:input"Com: > ";Fn$
cls
if Fn$="List" then [List_Recs]
if Fn$="Clr" then cls:gosub [Start]
if Fn$="?" then [HLP]
if Fn$="Ins" then [Man]
if Fn$="" then gosub [Start]
'if Fn$<>"List" or Fn$<>"Ins" or Fn$<> "Clr" then [Sys_Err]'** Problem Line
on error goto [Err]

[Open_File]' *  Open Selected File Name
open Fn$ for input as #1
gosub [Read]
close #1:end

[Err]'* trap File not Found Err
if Err=53 then gosub [New]' * File Does not exist. Prompt user if they wish to Add it

end

[New]'* If file not found, ask user if they want to create it
locate 5,8:print "File named '";Fn$;"' Not found"
locate 5,9:input"Create it? <y/n>:";Yn$
if Yn$="y" then [Cr_New]
cls
gosub [Start]

[Read]' * If record found, Print contents on Scrn.
locate 7,4:print"FILE NAME: ";Fn$
locate 5,5:print"----------------------------------------------------------------------------------------------"
let a=7:let b=1
[Read_Loop]
input #1,a$(b)
locate 6,a:print a$(b)
let a=a+1
if eof(#1)=0 then [Read_Loop]
close #1
locate 5,29:Input"Press 'Enter'-> ";rt$
cls
gosub [Start]



[Cr_New]' * Allow user Add Data to the new Datafile
cls
locate 5,3:print"Enter Data for File Named ";Fn$
open Fn$ for output as #2
let a=1:let b=5
10 locate 5,b:input"";d$(a)
if d$(a)="" then gosub [Save]
let a=a+1:let b=b+1
goto 10

[Save]' * Save all lines of data entered.
for y=1 to a
print #2,d$(y)
next y


[Add]'* Add new record to File Listing
open"list_Recs" for Append as #1
print #1,Fn$;",";date$("mm/dd/yy")
close #1

print"New File Created "
Input"Press 'Enter'-> ";rt$
cls
gosub [Start]

[List_Recs]'* print list of existing Recs on Scrn.
 open"list_Recs" for input as #3
 let a=9
 locate 6,3:print"*** FILE LISTING ***"
 locate 6,4:print"--------------------"
 locate 3,6:print"=============================================="
 locate 3,7:print"|  FILE NAME                  CREATION DATE  |"
 locate 3,8:print"=============================================="

 [Loop]' * Cycle Recs in list file, print on Scrn
 input #3,Fname$,CD$
 locate 5,a:print Fname$
 locate 35,a:print CD$
 let a=a+1
 if eof(#3)=0 then gosub [Loop]
 close #3
 'locate 3,30:print"{ Press 'Enter' to Clear Screen }"
 gosub [Start]

[Sys_Err]' * User entered a non understood Command
locate 3,27:print"<<< SYNTAX ERROR >>>":playwave "Ding"
gosub [Start]

[HLP]
cls
locate 30,2:print"  COMMAND LIST "
locate 30,3:print"----------------"
locate 10,5:print"COMMAND                  ACTION"
locate 10,6:print"==============================================================="
locate 10,8:print" List                   List Saved File Names"
locate 10,10:print" ?                      This Help File"
locate 10,12:print" Ins                    Instructions of Use"
locate 10,23:input"Press 'Enter' to Return to Command Prompt -> ";rt$
cls
gosub [Start]

[Man]
cls
locate 34,4:print" INSTRUCTIONS"
locate 34,5:print"--------------"
locate 6,7:print" (1) BASIC COMMANDS "
locate 6,9:print"  (1.1) Entering Commands "
locate 6,10:print"  -------------------------"
locate 6,11:print"when Entering a command, Be sure to Capitalize the first Letter."
locate 6,12:print"if this is Omitted, or a typo Occurs, a Syntext error will Be"
locate 6,13:print"displayed,and you will be returned to the Command prompt"
locate 6,15:print"(2) FILE CREATION AND RECALL"

locate 6,17:print"  ---------------------------"
locate 6,18:Print" To create a New File, Simply Enter its Name at the Command Prompt."
locate 6,19:print" If the File does not already exist,the system will prompt:"
locate 6,20:print"'File Name' does not Exist, Create it ? <y/n>"
locate 6,22:print" Entering 'y' will prompt you to 'Enter Data' for the file."
locate 6,23:print" Press 'Enter at the end of Each line of Text,to move to the next line."
locate 6,24:print" to save your text:press 'Enter' at the next empty prompt."
locate 6,26:print" Entering 'n' clears the screen, and returns you to the command prompt"
locate 6,27:input "NEXT -> ";n$

' * Page-2
let Flag$="p2"
cls
locate 34,4:print" INSTRUCTIONS"
locate 34,5:print"--------------"
locate 6,7:print"(2) FILE CREATION AND RECALL"
locate 6,9:print"  (2.2) RECALLING SAVED RECORDS "
locate 6,10:print" To Recall a saved record,Enter its name at the command Prompt,and the file will"
locate 6,11:print" be opened and appear on the screen"
locate 6,13:print" (2.3) LISTING SAVED RECORDS"
locate 6,14:print" to list records saved on the system, Enter 'Lst' at the command prompt,"
locate 6,15:print" and a roster of saved files and their creation dates,will be printed on the screen."
20 locate 6,27:print "Enter 'p' for Prevous page or 'e' to return to Command Prompt -> ";n$
locate 72,27:input"";n$
if n$="p" and Flag$="p2" then [Man]
if n$="e" then cls:gosub [Start]
goto 20



[Rod]

If [start] is a subroutine it should end in a return should it not? You might be better using a loop, do while, that loops till the condition is correct. You can use on error but it needs to be contained in this loop.

So it’s all about program flow and avoiding jumping around with Gosub that never finds a return.

[tsh73]

Yep.
13 GOSUB and not a single RETURN.
You are using it wrong!

(if you never gonna return just use plain GOTO)

[Rod]

If you are going to start to use gosub correctly you should imagine the code returning to the line under the gosub line.

If you use goto you would be looping back to [start]. A perfectly valid program flow, looping back to [start] if there is an error. But it is really a loop which you could code with a loop structure like do while.

But let’s get you using goto and gosub correctly first of all.

[tsh73]

I have a guess that if you have handful of GOSUB and no RETURN -
you will use some of computer memory for storing return address
But that's all
It will work, for a while.
(I just looped GOSUB, it got out of memory after 5 700 000 loops. And it happens under one minute.
So if you use it instead of FOR, it will break pretty fast)

So please read on GOSUB / RETURN, think if you need it or not, if not use GOTO.

Now, other problems with code
You see the line
if Err=53 then goto [New]' * File Does not exist. Prompt user if they wish to Add it
?
But it will never work.
I just put
print "Err=";Err
print "Err$=";Err$
just above it, and got
Err=0
Err$=OS Error: Íå óäàåòñÿ íàéòè óêàçàííûé ôàéë.

(second is some locale specifoc gibberish translated like "file cannot be found")
See? It never happens to be 53

Ok
let's suppose we check Err$ instead, and it works reliably.

Problem is, in JB you can turn error handling ON
but cannot turn it OFF!
And any other error (like
[List_Recs]'* print list of existing Recs on Scrn.
 open"list_Recs" for input as #3

- I have no such file so it errors
)
will jump to the same place as first time.

Not really helpful.
(folks got around it by putting code prone to errors in the sub/function, and putting ON ERROR there.
This way, it does not work ofter leaving the function.
)

But
Help file has article
* Language Syntax and Usage •Just BASIC Language
** File Operations
*** Testing for File Existence
which has example how to check if file exist before opening it. Without triggering error.

It has a function
function fileExists(path$, filename$)
and example of using it. Have a look.

[tsh73]

Have I been blocked

blocked == cannot post, at all
so no
Keep calm and carry on
Sometimes things just vanish. Try again.

I think if there was a reason your post could be deleted (by violating some policy for example?), you will get PM by moderators explaining that.

[Rod]

The most obvious reason for this anomaly is thst you neglected to press the POST button after composing the message. I have done that often and then wondered where my message was.