Posted by oxaric on November 23, 2008
Here are some simple C++ functions I thought I’d put up. Maybe I’ll put up more later.
The 3 functions are:
string trim( string line );
string prepareLineForLinux( string line );
bool isWhiteLine( string line );
trim()
input: receives a string
output: returns a new string with all leading and ending whitespace removed
prepareLineForLinux()
input: receives a string
output: returns a new string that will be acceptable to be used in a Linux system call. Checks for Linux special characters and includes the necessary delimiters.
isWhiteLine()
needs the function trim()
input: receives a string
output: returns true if the string is empty otherwise false
Click to directly download stringfunctions.cpp
// filename 'stringfunctions.cpp'
// Use: Has some functions used for manipulating strings
// By: Louis Casillas, oxaric@gmail.com
#include <iostream>
#include <string>
using namespace std;
string trim( string line );
string prepareLineForLinux( string line );
bool isWhiteLine( string line );
// needs the function trim()
// input: receives a string
// output: returns true if the string is empty otherwise false
bool isWhiteLine( string line )
{
string temp = trim(line);
if ( (temp == "") || (temp == "\n") )
{
return true;
}
else
{
return false;
}
}
// input: receives a string
// output: returns a new string with all leading and ending whitespace removed
string trim( string line )
{
if ( line.empty() )
{
return "";
}
int string_size = (int)(line.length());
int beginning_of_string = 0;
// the minus 1 is needed to start at the first character
// and skip the string delimiter
int end_of_string = string_size - 1;
bool encountered_characters = false;
// find the start of chracters in the string
while ( (beginning_of_string < string_size) && (!encountered_characters) )
{
// if a space or tab was found then ignore it
if ( (line[ beginning_of_string ] != ' ') && (line[ beginning_of_string ] != '\t') )
{
encountered_characters = true;
}
else
{
beginning_of_string++;
}
}
// test if no characters were found in the string
if ( beginning_of_string == string_size )
{
return "";
}
encountered_characters = false;
// find the character in the string
while ( (end_of_string > beginning_of_string) && (!encountered_characters) )
{
// if a space or tab was found then ignore it
if ( (line[ end_of_string ] != ' ') && (line[ end_of_string ] != '\t') )
{
encountered_characters = true;
}
else
{
end_of_string--;
}
}
// return the original string with all whitespace removed from its beginning and end
// + 1 at the end to add the space for the string delimiter
return line.substr( beginning_of_string, end_of_string - beginning_of_string + 1 );
}
// input: receives a string
// output: returns a new string that will be acceptable to be used in a Linux system call
// checks for Linux special characters and includes the necessary delimiters
string prepareLineForLinux( string line )
{
string return_string = "";
int i = 0;
int string_size = (int)(line.size() - 1);
while ( i <= string_size )
{
if ( line[i] == ' ' )
{
return_string += "\\ ";
}
else if ( line[i] == '\'' )
{
return_string += "\\\'";
}
else if ( line[i] == '\\' )
{
return_string += "\\\\";
}
else if ( line[i] == '(' )
{
return_string += "\\(";
}
else if ( line[i] == ')' )
{
return_string += "\\)";
}
else if ( line[i] == '[' )
{
return_string += "\\[";
}
else if ( line[i] == ']' )
{
return_string += "\\]";
}
else if ( line[i] == '&' )
{
return_string += "\\&";
}
else
{
return_string += line[i];
}
i++;
}
return return_string;
}
int main()
{
cout << "\ntrim() function\n---\n";
string test1 = " \t Hello World!\t \t ";
cout << "\nOriginal Text: |" << test1 << "|\n";
cout << "Trimmed Text: |" << trim(test1) << "|\n";
cout << "\nprepareLineForLinux() function\n---\n";
string test2 = "mv /this is/ my/ directory[0]/file-(4).txt";
cout << "\nOriginal Text: |" << test2 << "|\n";
cout << "Prepared Text: |" << prepareLineForLinux(test2) << "|\n";
cout << "\nisWhiteLine() function\n---\n";
string test3 = " ";
cout << "\nOriginal Text: |" << test3 << "|\n";
cout << "isWhiteLine?: " << isWhiteLine(test3) << " <--- 0=NO, 1=YES \n";
return 0;
}
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This entry was posted on November 23, 2008 at 21:25 and is filed under C/C++, Linux, Programming.
Tagged: bash, c++, convert, cpp, function, Linux, prepare, space, string, system, trim, whitespace. You can follow any responses to this entry through the RSS 2.0 feed.
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