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5
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1 /* strstr.c -- return the offset of one string within another |
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2 Copyright (C) 1989, 1990 Free Software Foundation, Inc. |
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3 |
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4 This program is free software; you can redistribute it and/or modify |
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5 it under the terms of the GNU General Public License as published by |
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6 the Free Software Foundation; either version 2, or (at your option) |
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7 any later version. |
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8 |
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9 This program is distributed in the hope that it will be useful, |
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10 but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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12 GNU General Public License for more details. |
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13 |
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14 You should have received a copy of the GNU General Public License |
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15 along with this program; if not, write to the Free Software |
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16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
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17 |
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18 /* Author: |
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19 Mike Rendell Department of Computer Science |
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20 michael@garfield.mun.edu Memorial University of Newfoundland |
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21 ..!uunet!garfield!michael St. John's, Nfld., Canada |
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22 (709) 737-4550 A1C 5S7 |
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23 */ |
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24 |
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25 /* Return the starting address of string S2 in S1; |
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26 return 0 if it is not found. */ |
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27 |
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28 char * |
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29 strstr (s1, s2) |
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30 char *s1; |
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31 char *s2; |
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32 { |
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33 int i; |
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34 char *p1; |
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35 char *p2; |
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36 char *s = s1; |
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37 |
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38 for (p2 = s2, i = 0; *s; p2 = s2, i++, s++) |
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39 { |
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40 for (p1 = s; *p1 && *p2 && *p1 == *p2; p1++, p2++) |
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41 ; |
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42 if (!*p2) |
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43 break; |
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44 } |
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45 if (!*p2) |
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46 return s1 + i; |
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47 |
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48 return 0; |
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49 } |
