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DCC C Compiler Reference

string.h: String handling

String handling (`string.h`)¶

Include string.h for byte-string and raw memory operations.

Functions¶

Function	Summary
`void * memchr( const void *, int, size_t )`	Find the first matching byte within n bytes of an object.
`int memcmp( const void , const void , size_t )`	Compare n bytes from two objects.
`void * memcpy( void , const void , size_t )`	Copy n bytes from a non-overlapping source object to a destination object.
`void * memmove( void , const void , size_t )`	Copy n bytes between objects, safely handling overlap.
`void * memset( void *, int, size_t )`	Fill n bytes of an object with the low byte of c.
`char * strcat( char , const char )`	Append one string to another.
`char * strchr( const char *, int )`	Find the first occurrence of a character in a string.
`int strcmp( const char , const char )`	Lexicographic string comparison.
`int strcoll( const char , const char )`	Locale-independent string comparison, equivalent to strcmp in dcc.
`char * strcpy( char , const char )`	Copy a string including its terminating NUL.
`size_t strcspn( const char , const char )`	Length of the leading segment containing none of the reject characters.
`char * strdup( const char * )`	Allocate and return a heap copy of a string.
`char * strerror( int )`	Return text for an error number.
`int stricmp( const char , const char )`	Case-insensitive lexicographic string comparison (ASCII only).
`size_t strlen( const char * )`	Length of a string excluding the terminating NUL.
`char * strncat( char , const char , size_t )`	Append at most n characters from one string to another, then write a NUL.
`int strncmp( const char , const char , size_t )`	Compare at most n characters from two strings.
`char * strncpy( char , const char , size_t )`	Copy at most n characters from one string to another, padding with NULs.
`char * strpbrk( const char , const char )`	Find the first character from a set in a string.
`char * strrchr( const char *, int )`	Find the last occurrence of a character in a string.
`size_t strspn( const char , const char )`	Length of the leading segment containing only accepted characters.
`char * strstr( const char , const char )`	Find the first occurrence of a substring in a string.
`char * strtok( char , const char )`	Split a string into tokens separated by delimiter characters.
`size_t strxfrm( char , const char , size_t )`	Transform s2 for strcoll comparison into s1, writing at most n chars; returns strlen(s2).

Runtime model¶

The string and memory functions operate on byte strings and raw byte buffers. strcoll is equivalent to strcmp; the DCC C Compiler has no locale model.

String and memory operations¶

#include <string.h>

char dst[16];
strcpy(dst, "hello");
if (strcmp(dst, "hello") == 0)
    memset(dst, 0, sizeof dst);

Tokenizing a copy of a string with strtok writes NULs into the buffer. Pass only modifiable strings; do not pass string literals:

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

char line[] = "alpha,beta,,gamma";
char *tok = strtok(line, ",");
while (tok) {
    puts(tok);                 /* alpha, beta, gamma */
    tok = strtok(NULL, ",");
}

strdup is the exception

Most string routines link nothing extra, but strdup allocates, so it inherits the whole malloc chain. See the appendix.