- The C Standard Library
- C Standard Library Resources
- C Programming Resources
- Selected Reading
Description
The C library function int system(const char *command) passes the command name or program name specified by command to the host environment to be executed by the command processor and returns after the command has been completed.
Note In Visual C 2005 and in Visual C 2008, you must add the common language runtime support compiler option (/clr:oldSyntax) to successfully compile the previous code sample. To add the common language runtime support compiler option, follow these steps: Click Project, and then click ProjectName Properties. Note ProjectName is a placeholder for the name of the project. Passing char. from c dll Struct to c#. GitHub Gist: instantly share code, notes, and snippets. May 07, 2010 strstr can be used with (non-const) char. arguments. The fact that it takes const char. simply means that it is guranteed that it won't modify your strings. The problem here is that Test and SearchString are pointers. No memory is reserved to hold the user input, thus the lines cin Text; and cin SearchString; overwrite data that may be useful to your program and the program crashes as a.
Declaration
Following is the declaration for system() function.
Parameters
command − This is the C string containing the name of the requested variable.
Return Value
The value returned is -1 on error, and the return status of the command otherwise.
Example
The following example shows the usage of system() function to list down all the files and directories in the current directory under unix machine.
Let us compile and run the above program that will produce the following result on my unix machine −
The following example shows the usage of system() function to list down all the files and directories in the current directory under windows machine.
Let us compile and run the above program that will produce the following result on my windows machine −
- The C Standard Library
- C Standard Library Resources
- C Programming Resources
- Selected Reading
String To Const Char
Description
The C library function char *strstr(const char *haystack, const char *needle) function finds the first occurrence of the substring needle in the string haystack. The terminating '0' characters are not compared.
Declaration
Following is the declaration for strstr() function.
Parameters
haystack − This is the main C string to be scanned.
needle − This is the small string to be searched with-in haystack string.
Return Value
This function returns a pointer to the first occurrence in haystack of any of the entire sequence of characters specified in needle, or a null pointer if the sequence is not present in haystack.
Example
The following example shows the usage of strstr() function.
Let us compile and run the above program that will produce the following result −