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Annotation of coherent/a/usr/man/ALL/memcmp, revision 1.1.1.1

1.1       root        1: 
                      2: 
                      3: memcmp()                 String Function                 memcmp()
                      4: 
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                      6: 
                      7: 
                      8: Compare two regions
                      9: 
                     10: #include <string.h>
                     11: iinntt mmeemmccmmpp(_r_e_g_i_o_n_1, _r_e_g_i_o_n_2, _c_o_u_n_t);
                     12: cchhaarr *_r_e_g_i_o_n_1; cchhaarr *_r_e_g_i_o_n_2; uunnssiiggnneedd iinntt _c_o_u_n_t;
                     13: 
                     14: memcmp compares  region1 with region2 character  by character for
                     15: count characters.
                     16: 
                     17: If every  character in region1 is  identical to its corresponding
                     18: character in region2, then memcmp returns zero.  If it finds that
                     19: a character  in region1 has a numeric value  greater than that of
                     20: the corresponding character  in region2, then it returns a number
                     21: greater than zero.  If it finds that a character in region1 has a
                     22: numeric value less  than less that of the corresponding character
                     23: in region2, then it returns a number less than zero.
                     24: 
                     25: For example, consider the following code:
                     26: 
                     27: 
                     28:         char region1[13], region2[13];
                     29:         strcpy(region1, "Hello, world");
                     30:         strcpy(region2, "Hello, World");
                     31:         memcmp(region1, region2, 12);
                     32: 
                     33: 
                     34: memcmp  scans  through  the  two  regions  of  memory,  comparing
                     35: region1[0] with  region2[0], and so  on, until it  finds two cor-
                     36: responding ``slots'' in the arrays whose contents differ.  In the
                     37: above example, this will occur when it compares region1[7] (which
                     38: contains `w') with region2[7] (which contains `W').  It then com-
                     39: pares the two letters to  see which stands first in the character
                     40: table used  in this  implementation, and returns  the appropriate
                     41: value.
                     42: 
                     43: memcmp  differs from  the string comparison  routine strcmp  in a
                     44: number of ways.   First, memcmp compares regions of memory rather
                     45: than strings;  therefore, it does  not stop when  it encounters a
                     46: null character.
                     47: 
                     48: Also, memcmp can be used to  compare an int array with a char ar-
                     49: ray is permissible because memcmp simply compares areas of data.
                     50: 
                     51: ***** See Also *****
                     52: 
                     53: strcmp(), string functions, string.h
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                     64: COHERENT Lexicon                                           Page 1
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