Making an API

function fileGetInfo(path,file,line)
fs.exists(path)
if (fs.exists(path) == true) then
    fs.exists(file)
    if (fs.exists("pos") == true) then
	    shell.setDir(path)
	    local files = fs.open(file, "r")
	    local fileData = {}
	    local lines = file.readLine()
	    repeat
	    table.insert(fileData,lines)
	    lines = files.readLine()
	    until lines == nil
	    file.close()
	    info = filedata[line]
	    return info
	    end
    end
end

function fileGetInfo(path,file,lineNum)
	local path = fs.combine(path, file) --combine the path and file name.  You could even just use one argument, the full path.
	if fs.exists(path) then
		local fileHandle = io.open(file, "r") --open our file with the io library, because it is better.
		local fileData = {}
		if fileHandle then --check the file handle anyway, just to make sure.
			for line in fileHandle:lines() do --for every line in the file,
				table.insert(fileData, line) --add the line to the table.
			end
			file:close()
			if fileData[lineNum] then --if our line number refers to an actual line of the file.
				return fileData[lineNum]
			else
				return nil, "Line number out of range!"
			end
		else
			return nil, "Error opening file!"
		end
	else
		return nil, "File not found!"
	end
end

function fileGetInfo(path,file,lineNum)
    local path = fs.combine(path, file) --combine the path and file name.  You could even just use one argument, the full path.
    if fs.exists(path) then
        local fileHandle = io.open(path, "r") --open our file with the io library, because it is better.
        local fileData = {}
        if fileHandle then --check the file handle anyway, just to make sure.
            for line in fileHandle:lines() do --for every line in the file,
                table.insert(fileData, line) --add the line to the table.
            end
            fileHandle:close()
            if fileData[lineNum] then --if our line number refers to an actual line of the file.
                return fileData[lineNum]
            else
                return nil, "Line number out of range!"
            end
        else
            return nil, "Error opening file!"
        end
    else
        return nil, "File not found!"
    end
end

Wing, on 29 October 2012 - 12:48 AM said:

omg, this is complicated, now getting attempt to index ? (a nil value)
edit: ill check back tomorrow

function fileGetInfo(path,file,lineNum)
    local path = fs.combine(path, file) --combine the path and file name.  You could even just use one argument, the full path.
    if fs.exists(path) then
	    local fileHandle = io.open(path, "r") --open our file with the io library, because it is better.
	    local fileData = {}
	    if fileHandle then --check the file handle anyway, just to make sure.
		    for line in fileHandle:lines() do --for every line in the file,
			    table.insert(fileData, line) --add the line to the table.
		    end
		    fileHandle:close()
		    if fileData[lineNum] then --if our line number refers to an actual line of the file.
			    return fileData[lineNum]
		    else
			    return "Line number out of range!"
		    end
	    else
		    return "Error opening file!"
	    end
    else
	    return "File not found!"
    end
end

i = tonumber(read())
print(fileGetInfo("","lol",i))

sIdEkIcK_, on 29 October 2012 - 06:39 PM said:

Wing, on 29 October 2012 - 12:48 AM said:

omg, this is complicated, now getting attempt to index ? (a nil value)
edit: ill check back tomorrow

Whats the number that was with the line?

Edit: I tested it and it works perfectly .. I removed the 'nil's where it returns because it then doesn't print the error, no clue why.

function fileGetInfo(path,file,lineNum)
    local path = fs.combine(path, file) --combine the path and file name.  You could even just use one argument, the full path.
    if fs.exists(path) then
	    local fileHandle = io.open(path, "r") --open our file with the io library, because it is better.
	    local fileData = {}
	    if fileHandle then --check the file handle anyway, just to make sure.
		    for line in fileHandle:lines() do --for every line in the file,
			    table.insert(fileData, line) --add the line to the table.
		    end
		    fileHandle:close()
		    if fileData[lineNum] then --if our line number refers to an actual line of the file.
			    return fileData[lineNum]
		    else
			    return "Line number out of range!"
		    end
	    else
		    return "Error opening file!"
	    end
    else
	    return "File not found!"
    end
end

i = tonumber(read())
print(fileGetInfo("","lol",i))

This wasn't tested in an API though.

Lyqyd, on 29 October 2012 - 06:53 PM said:

sIdEkIcK_, on 29 October 2012 - 06:39 PM said:

— snip

The nil return followed by an error string is a lua convention. How do you now tell the difference between an error and a line in a file that is identical to the error strings? The nils were there for a reason and should not be removed.

for line in fileHandle:lines() do --for every line in the file,

function fileGetInfo(path,file,lineNum)
	local path = fs.combine(path, file) --combine the path and file name.  You could even just use one argument, the full path.
	if fs.exists(path) then
		local fileHandle = fs.open(path, "r") --open our file with the io library, because it is better.
		local fileData = {}
		if fileHandle then --check the file handle anyway, just to make sure.
			repeat
				line = fileHandle.readLine()--for every line in the file,
				table.insert(fileData, line) --add the line to the table.
			until line == nil
			fileHandle.close()
			if fileData[lineNum] then --if our line number refers to an actual line of the file.
				return fileData[lineNum]
			else
				return nil, "Line number out of range!"
			end
		else
			return nil, "Error opening file!"
		end
	else
		return nil, "File not found!"
	end
end

term.clear() term.setCursorPos(1,1)
filePath = read()
fileName = read()
fullPath = fs.combine(filePath, fileName) -- was just to check
lineNumber = tonumber(read())
os.loadAPI("gi")
print("File Path: "..filePath.."nFile Name: "..fileName.."nFull Path: "..fullPath.."nLine Number: "..lineNumber.."n")
print(gi.fileGetInfo(filePath,fileName,lineNumber))

if info then print(info) else print(errormessage) end

sIdEkIcK_, on 29 October 2012 - 07:22 PM said:

Tested it using it as an API and it works fine. The error you're getting might be because of this line:

for line in fileHandle:lines() do --for every line in the file,

function fileExec(path,file,path2,file2)
local path = fs.combine(path, file)
local path2 = fs.combine(path2,file2)
if fs.exists(path) then
local fileHandle = fs.open(path, "r")
local fileData = {}
	 if fileHandle then
	 repeat
		  line = fileHandle.readLine()
			table.insert(fileData, line)
		until line == nil
		 fileHandle.close()
		 local fileHandle2 = fs.open(path2,"w")
		 if filehandle2 then
		 data = 1
			 repeat
			 fileHandle2.writeLine(fileData[data])
				 data = data +1
			 until (fileData[data] == nil)
			 fileHandle2.close()
		 else
		 return nil, "Error opening file!"
			 end
else
		 return nil, "Error opening file!"
		 end
else
		return nil, "File not found!"
		end
end

function fileExtract(path,file,path2,file2)
local path3 = path2
local file3 = file2
local path = fs.combine(path, file)
local path2 = fs.combine(path2,file2)
if fs.exists(path) then
  local fileHandle = fs.open(path, "r")
  local fileData = {}
	 if fileHandle then
	  repeat
		   line = fileHandle.readLine()
		    table.insert(fileData, line)
		 until line == nil
		 fileHandle.close()
		 local fileHandle2 = fs.open(path2,"w")
		 if fileHandle2 then
		  data = 1
			 repeat
			   fileHandle2.writeLine(fileData[data])
				  data = data +1
			 until (fileData[data] == nil)
			 fileHandle2.close()
		 else
		  return nil, "Error opening file!"
			 end
  else
		 return nil, "Error opening file!"
		 end
else
	    return nil, "File not found!"
	    end
end