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strcmp
Compare Two Null-Terminated Strings
| Portability: | ISO/ANSI C conforming, UNIX compatible |
| SYNOPSIS | |
| DESCRIPTION | |
| RETURN VALUE | |
| CAUTION | |
| IMPLEMENTATION | |
| EXAMPLE | |
| RELATED FUNCTIONS | |
| SEE ALSO |
| SYNOPSIS |
#include <string.h>int strcmp(const char *str1, const char *str2);
| DESCRIPTION |
strcmpcompares two character strings (str1 and str2) using the standard EBCDIC collating sequence. The return value has the same relationship to 0 as str1 has to str2. If two stringsare equal up to the point at which one terminates (that is, contains a nullcharacter), the longer string is considered greater.
| RETURN VALUE |
The return value from strcmp is 0 if the two strings are equal, less than 0 if str1 compares less than str2, andgreater than 0 if str1 compares greaterthan str2. No other assumptions shouldbe made about the value returned by strcmp.
| CAUTION |
If one of the arguments of strcmp is not properly terminated, a protection or addressing exceptionmay occur. If one of the arguments to the built-in version of strcmp is a constant, the compiler generates a CLC instruction to performthe entire comparison. If the variable argument is not null terminated, thecharacter-by-character comparison may perform as expected, but a comparisonby the CLC instruction may cause an addressing exception in rare cases.
| IMPLEMENTATION |
The compiler generates inline code for strcmp unless strcmp is undefined (by an #undef statement)to prevent this. The inline code may still call a library routine in specialcases.
| EXAMPLE |
#include <lcstring.h>#include <stdio.h>#include <stdlib.h>main(){ char command[20]; int n = 0; for(;;) { ++n; printf("Enter command # %d\n", n); puts("Enter quit to terminate/any other command to continue"); gets(command_; if (strcmp(command, "quit") == 0) break; /* Determine whether command is equal to quit. */ strlwr(command); if (strcmp(command, "quit") == 0) exit(0); puts("Did you meant to say quit? (Case is significant.)"); }}
| RELATED FUNCTIONS |
memcmp, strcoll, strncmp, strxfrm
| SEE ALSO |
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