untyped files: what changed

Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.

Title: untyped files

New		Line
1	+	## Untyped text file
2	+
3	+	An untyped text file is suitable for processing files of any size. With untyped files, the content of a file is read line by line. Conversely, the file is written line by line. The data records of an untyped file can be of different lengths.
4	+
5	+	## Create file
6	+
7	+	``` pascal
8	+	var
9	+	datFile : TextFile; // or: datFile: text
10	+	strName : String;
11	+	sinContent : Single;
12	+	begin
13	+	Assign(datFile, 'example.txt'); // Assigns the name of the file to the variable datFile and opens the file
14	+	ReWrite(datFile); // The old file is overwritten
15	+	strName := 'qwert';
16	+	sinContent := 1800.23;
17	+	WriteLn(datFile, strName, sinContent); // Writes the first record to the new file
18	+	...
19	+	end;
20	+	```
21	+
22	+	In the OBJPFC or DELPHI compiler mode, the AssignFile procedure is available in addition to Assign to avoid confusion with TPersistent.Assign.
23	+
24	+	## Open file
25	+
26	+	``` pascal
27	+	var
28	+	datFile : TextFile;
29	+	strName : String;
30	+	sinContent : Single;
31	+	begin
32	+	Assign(datFile, 'example.txt'); // Assigns the name of the file to the datFile variable
33	+	Reset(datFile); // Sets the file pointer to the beginning of the file
34	+	ReadLn(datFile, strName, sinContent); // Reads the first line from the file
35	+	ReadLn(datFile, strName, sinContent); // Reads the second line from the file
36	+	...
37	+	end;
38	+	```
39	+
40	+	## Close file
41	+
42	+	``` pascal
43	+	var
44	+	datFile : TextFile;
45	+	strName : String;
46	+	sinContent : Single;
47	+	begin
48	+	...
49	+	Close(datFile); // closes the file
50	+	end;
51	+	```
52	+
53	+	Similar to AssignFile / Assign, the CloseFile procedure is available in OBJPFC or DELPHI compiler mode.
54	+
55	+	## Append a record to an existing file
56	+
57	+	For text files (untyped files), a data record can be added to the end of the file using the Append command.
58	+
59	+	``` pascal
60	+	var
61	+	datFile : TextFile;
62	+	strName : String;
63	+	sinContent : Single;
64	+	begin
65	+	Assign(datFile, 'example.txt'); // Assigns the name of the file to the datFile variable
66	+	Append(datFile); // Opens the file for write access and adds records to the end of the file
67	+	strName := 'sdf' ;
68	+	sinContent : = 2001.21 ;
69	+	WriteLn(datFile, strName, sinContent); // Writes another record to the new file
70	+	Close(datFile); // Closes the file
71	+	```
72	+
73	+	## Read file completely
74	+
75	+	``` pascal
76	+	var
77	+	datFile : TextFile;
78	+	strName : String;
79	+	sinContent : Single;
80	+	begin
81	+	Assign(datFile, 'example.txt');
82	+	Reset(datFile);
83	+
84	+	while not eof(datFile) // As long as data can still be read
85	+	do begin
86	+	read(datFile, strName, sinContent); // Read file content
87	+	end;
88	+
89	+	Close(datFile);
90	+	end;
91	+	```
92	+
93	+	## See also
94	+
95	+	- [[File types]]
96	+
97	+	---
98	+	From the Free Pascal wiki, page "untyped files", as it stood on 2022-01-29 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).

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