FindPattern
int FindPattern (char buffer[], int startingIndex, ssize_t numberOfBytes, char pattern[], int caseSensitive, int startFromRight);
Purpose
Searches a character buffer for a pattern of bytes. The string pattern specifies the pattern of bytes. FindPattern returns the position within the buffer where the pattern was found.
Example Code
The following example returns 4, which is the index of the second of the three occurrences of ab in the string 1ab2ab3ab4. FindPattern skips the first occurrence because startingIndex is 3. Of the two remaining occurrences, FindPattern finds the leftmost occurrence because startFromRight is zero.
ndx = FindPattern ("1ab2ab3ab4", 3, -1, "AB", 0, 0);
The following example returns 7, which is the index of the rightmost occurrence of ab, because startFromRight is a nonzero value.
ndx = FindPattern ("1ab2ab3ab4", 3, -1, "AB", 0, 1);
Parameters
| Input | ||
| Name | Type | Description |
| buffer | char [] | Buffer to search for the pattern. |
| startingIndex | int | Zero–based index specifying the location within buffer at which to begin searching for the pattern. |
| numberOfBytes | ssize_t | Number of bytes to search. If numberOfBytes is –1, FindPattern searches the set of bytes that starts at position startingIndex of buffer up to the first ASCII NUL. The function returns an error if you pass a value greater than UINT_MAX. |
| pattern | char [] | NUL–terminated string specifying the pattern of bytes to search for. |
| caseSensitive | int | Specify a nonzero value or select Yes in the function panel to match characters on a case-sensitive basis. Specify 0 or select No in the function panel to match characters on a case-insensitive basis. |
| startFromRight | int | Specify a nonzero value or select Yes in the function panel to find the rightmost occurrence of the pattern in the buffer. Specify 0 or select No in the function panel to find the leftmost occurrence of the pattern in the buffer. |
Return Value
| Name | Type | Description | ||
| result | int | Index in buffer where FindPattern finds the first byte of the pattern. The index is zero–based and is relative to the first byte of the buffer variable.
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Additional Information
Library: Formatting and I/O Library
Include file: formatio.h
LabWindows/CVI compatibility: LabWindows/CVI 3.0 and later
Examples
Refer to the following examples that use the FindPattern function:
- apps\daqmthread\daqMT.cws
Open example - toolbox\msgdemo.cws
Open example