Solved

Find + escape(replace) a (\)character in a path + filename from command line.

Posted on 2003-12-04
3
815 Views
Last Modified: 2010-08-05
I have written a small program that will be run on Win NT4 and W2k from a batch file.
I am using _findfirst to get the file attributes and I then open the file using fopen(name, a+) to read the number of records and I then append this info as a new record at the end of the file. (all works ok)

I want to be able to run the program from within the batch script using something like
program.exe c:\dir1\dir2\dirtest\filename.txt

I will copy the path+filename into a variable (say char *test) from argv[1].
I then need to escape(replace) the '\' characters in the string with '\\' so _findfirst and fopen will work correctly.
ie. I need test to contain c:\\dir1\\dir2\\dirtest\\filename.txt

I hope ive explained this clear enough as its been a while since ive been writing c.

int main(int argc, char* argv[])
{
  char *test;
  *test = argv[1]; //test now contains c:\dir1\dir2\dirtest\filename.txt
  //need to parse test so it contains c:\\dir1\\dir2\\dirtest\\filename.txt
...
...
}

Thanks.
0
Comment
Question by:diarmaid
3 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 125 total points
ID: 9874942
>>I then need to escape(replace) the '\' characters in the string with '\\' so _findfirst and fopen will work correctly.

No, you don't :o)

If you write

char* test="c:\\dir1\\dir2\\dirtest\\filename.txt";

the internal (binary) representation is 'c:\dir1\dir2\dirtest\filename.txt' - the double backslash is *ONLY* needed in C source code as a single backslash means something different. Input from the command line like the above will be processed correctly.
0
 
LVL 45

Expert Comment

by:Kdo
ID: 9875040
Hi diarmaid,

jkr's correct.

The backslash tells the compiler, "do not place this character (the backslash) in the string, insert the next character without interpretting it".  The entire backslash thing came to be so that you could put quotes into your message.  "This message contains a double quote (\")".  Without the backslash the quote in the parentheses would be interpretted as the end of string and you'd get a compilation error.

The C compiler interprets the backslash so that whatever follows it is placed into the string without question.  When your string contains double backslashes, the compiler treats the first one as an escape character and insterts the second into the actual string -- which is the effect that you want.

Kent
0
 
LVL 2

Author Comment

by:diarmaid
ID: 9875063
Thanks, as i said its been a while, forgot about that.
0

Featured Post

NAS Cloud Backup Strategies

This article explains backup scenarios when using network storage. We review the so-called “3-2-1 strategy” and summarize the methods you can use to send NAS data to the cloud

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This tutorial is posted by Aaron Wojnowski, administrator at SDKExpert.net.  To view more iPhone tutorials, visit www.sdkexpert.net. This is a very simple tutorial on finding the user's current location easily. In this tutorial, you will learn ho…
Summary: This tutorial covers some basics of pointer, pointer arithmetic and function pointer. What is a pointer: A pointer is a variable which holds an address. This address might be address of another variable/address of devices/address of fu…
The goal of this video is to provide viewers with basic examples to understand how to use strings and some functions related to them in the C programming language.
Video by: Grant
The goal of this video is to provide viewers with basic examples to understand and use nested-loops in the C programming language.

919 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

22 Experts available now in Live!

Get 1:1 Help Now