| Copying functions | |
| memccpy | Copy memory with specified terminator (POSIX extension) |
| memcpy | Copy memory |
| memmove | Safely copy overlapping memory |
| mempcpy | Copy memory (GNU extension) |
| strcat | Concatenate strings |
| strcpy | Copy string |
| strdup | Duplicate string (POSIX extension) |
| strlcat | Copy string up to a maximum length with terminator (BSD extension) |
| strlcpy | Copy string up to a maximum length with terminator (BSD extension) |
| strncat | Concatenate strings up to maximum length |
| strncpy | Copy string up to a maximum length |
| strndup | Duplicate string (POSIX extension) |
| Comparison functions | |
| memcmp | Compare memory |
| strcasecmp | Compare strings ignoring case (POSIX extension) |
| strcmp | Compare strings |
| strncasecmp | Compare strings up to a maximum length ignoring case (POSIX extension) |
| strncmp | Compare strings up to a maximum length |
| Search functions | |
| memchr | Search memory for a character |
| strcasestr | Find first case-insensitive occurrence of a string within string |
| strchr | Find character within string |
| strcspn | Compute size of string not prefixed by a set of characters |
| strncasestr | Find first case-insensitive occurrence of a string within length-limited string |
| strnchr | Find character in a length-limited string |
| strnlen | Calculate length of length-limited string (POSIX extension) |
| strnstr | Find first occurrence of a string within length-limited string |
| strpbrk | Find first occurrence of characters within string |
| strrchr | Find last occurrence of character within string |
| strsep | Break string into tokens (4.4BSD extension) |
| strspn | Compute size of string prefixed by a set of characters |
| strstr | Find first occurrence of a string within string |
| strtok | Break string into tokens |
| strtok_r | Break string into tokens, reentrant version (POSIX extension) |
| Miscellaneous functions | |
| memset | Set memory to character |
| strerror | Decode error code |
| strlen | Calculate length of string |