Use both read and write operation to the same file

[Curious]

I have a file to which I'll need to at first read until it locates the
last line of string.

According to content of the last line of string, I'll need to write
something to this file right after the last line of string.

This requires that I'll need a StreamReader at first (to read one line
at a time), until the last line is read.

Then I'll need a StreamWriter to point to the end of the file, and
write to it.

Questions:

1) Is there a single Stream type of object that I can use for both
reading and writing, because I'll need to write at the point where
read operation is done?

2) Is there a method in the Stream object that reads only the last
line from a file (instead of reading all of the lines of strings)?

[Cor Ligthert[MVP]]

Hi,

There is no StreamDoSomething

http://msdn.microsoft.com/en-us/library/system.io.aspx

A stream is in fact a stream of bytes. By the textstreams this can be
delimited by the CR and LF to break in so called lines of strings. Thereore
you can not get the last bytes of a string that starts with a CR and LF,
just because you don't know what is the last.

Cor

http://msdn.microsoft.com/en-us/library/system.io.aspx
"Curious" <fi********@yahoo.comschreef in bericht
news:2a**********************************@l42g2000 hsc.googlegroups.com...

>I have a file to which I'll need to at first read until it locates the
last line of string.

According to content of the last line of string, I'll need to write
something to this file right after the last line of string.

This requires that I'll need a StreamReader at first (to read one line
at a time), until the last line is read.

Then I'll need a StreamWriter to point to the end of the file, and
write to it.

Questions:

1) Is there a single Stream type of object that I can use for both
reading and writing, because I'll need to write at the point where
read operation is done?

2) Is there a method in the Stream object that reads only the last
line from a file (instead of reading all of the lines of strings)?

[=?Utf-8?B?RmFtaWx5IFRyZWUgTWlrZQ==?=]

Unless the file size is large, I think the easiest way would be the following:

string [] lines = System.IO.File.ReadAllLines("somefile.txt");
// do some manipulations with lines[lines.Count - 1];
System.IO.File.WriteAllLines("somefile.txt", lines);
"Curious" wrote:

I have a file to which I'll need to at first read until it locates the
last line of string.

According to content of the last line of string, I'll need to write
something to this file right after the last line of string.

This requires that I'll need a StreamReader at first (to read one line
at a time), until the last line is read.

Then I'll need a StreamWriter to point to the end of the file, and
write to it.

Questions:

1) Is there a single Stream type of object that I can use for both
reading and writing, because I'll need to write at the point where
read operation is done?

2) Is there a method in the Stream object that reads only the last
line from a file (instead of reading all of the lines of strings)?

[Curious]

Thanks for sharing!

[Curious]

Good to know that there is a way to get all of the lines in a single
operation, and get the last line!