Everything
7.4.13 <string.h>

Defines functions for handling character arrays.

Type

Definition Name

Description

Function

memcpy

Copies contents of a source storage area of a specified length to a destination storage area.

strcpy

Copies contents of a source string including the null character to a destination storage area.

strncpy

Copies a source string of a specified length to a destination storage area.

strcat

Concatenates a string after another string.

strncat

Concatenates a string of a specified length after another string.

memcmp

Compares two storage areas specified.

strcmp

Compares two strings specified.

strncmp

Compares two strings specified for a specified length.

memchr

Searches a specified storage area for the first occurrence of a specified character.

strchr

Searches a specified string for the first occurrence of a specified character.

strcspn

Checks a specified string from the beginning and counts the number of consecutive characters at the beginning that are not included in another string specified.

strpbrk

Searches a specified string for the first occurrence of any character that is included in another string specified.

strrchr

Searches a specified string for the last occurrence of a specified character.

strspn

Checks a specified string from the beginning and counts the number of consecutive characters at the beginning that are included in another string specified.

strstr

Searches a specified string for the first occurrence of another string specified.

strtok

Divides a specified string into some tokens.

memset

Sets a specified character for a specified number of times at the beginning of a specified storage area.

strerror

Sets an error message.

strlen

Calculates the length of a string.

memmove

Copies contents of a source storage area of a specified length to a destination storage area. Even if a part of the source storage area and a part of the destination storage area overlap, correct copy is performed.

 

Implementation-Defined Specifications

Item

Compiler Specifications

Error message returned by the strerror function

Refer to section 10.5.6, Standard Library Error Messages.

 

When using functions defined in this standard include file, note the following.

(1)

On copying a string, if the destination area is smaller than the source area, correct operation is not guaranteed.

Example

        char a[]="abc";
        char b[3];
              .
              .
              .
        strcpy (b, a);

In the above example, the size of array a (including the null character) is 4 bytes. Copying by strcpy overwrites data beyond the boundary of array b.

 

(2)

On copying a string, if the source area overlaps the destination area, correct operation is not guaranteed.

Example

        int a[ ]="a";
            :
            :
        strcpy(&a[1], a);
            :

In the above example, before the null character of the source is read, 'a' is written over the null character. Then the subsequent data after the source string is overwritten in succession.