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 | /* Written by Mike Rendell <[email protected]>. */
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19 |
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20 | /* Return the starting address of string S2 in S1;
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21 | return 0 if it is not found. */
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22 |
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23 | char *
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24 | strstr (char *s1, char *s2)
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25 | {
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26 | int i;
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27 | char *p1;
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28 | char *p2;
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29 | char *s = s1;
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30 |
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31 | for (p2 = s2, i = 0; *s; p2 = s2, ++i, ++s)
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32 | {
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33 | for (p1 = s; *p1 && *p2 && *p1 == *p2; ++p1, ++p2)
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34 | ;
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35 | if (!*p2)
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36 | break;
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37 | }
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38 | if (!*p2)
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39 | return s1 + i;
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40 |
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41 | return 0;
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42 | }
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