Compare part of an input string using strcmp() in C

Question

Normally strcmp is used with two arguments [e.g. strcmp(str1,"garden")], and it will return 0 if both are the same.

Is it possible to compare part of the input, say the first five character of the input? (for example, strcmp(str1,"garde",5))

#include <stdio.h>
#include<string.h>

int main(void) {

    char str1[] = "garden";

    if (strcmp(str1, "garden") == 0)
    {
        printf("1");
    }
    if (strcmp(str1, "garden", 6) == 0)
    {
        printf("2");
    }
    if (strcmp(str1, "garde", 5) == 0)
    {
        printf("3");
    }
    return 0;
}

You need strncmp http://www.cplusplus.com/reference/cstring/strncmp/ — goji, Dec 12 '12 at 03:34

score 16 · Accepted Answer · answered Dec 12 '12 at 03:35

16

Use strncmp:

if (strncmp(str, "test", 4) == 0) { printf("it matches!"); }

See http://www.cplusplus.com/reference/cstring/strncmp/ for more info.

answered Dec 12 '12 at 03:35

goji

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Hey Troy thanks for replying. Does it works with 3 arguments cuz I get this error, prog.c:10:29: error: macro "strcmp" passed 3 arguments, but takes just 2 – user1872384 Dec 12 '12 at 03:45

score 3 · Answer 2 · answered Dec 12 '12 at 03:35

3

You're looking for strncmp().

Keep in mind that C does not supports overloading, so each "variation" of the same function has an unique name.

answered Dec 12 '12 at 03:35

Crozin

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Hey Crozin, thanks. Which answer should I approve since both of you answer at about the same time lol... – user1872384 Dec 12 '12 at 03:47

Compare part of an input string using strcmp() in C

2 Answers2