| fclose | fflush |  |  | Close or flush a stream. | 
| ferror | feof | clearerr | fileno | Stream status inquiries. | 
| fopen | freopen | fdopen |  | Open a stream. | 
| fread | fwrite |  |  | Input/output. | 
| fseek | rewind | ftell |  | Reposition a file pointer in a stream. | 
| getc | getchar | fgetc | getw | Get a character or word from a stream. | 
| gets | fgets |  |  | Get a string from a stream. | 
| popen | pclose |  |  | Begin or end a pipe to/from a process. | 
| printf | fprintf | sprintf |  | Print formatted output. | 
| putc | putchar | fputc | putw | Put a character or word on a stream. | 
| puts | fputs |  |  | Put a string on a stream. | 
| scanf | fscanf | sscanf |  | Convert formatted input. | 
| setbuf | setvbuf |  |  | Assign buffering to a stream. | 
| system |  |  |  | Issue a command through the shell. | 
| tmpfile |  |  |  | Create a temporary file. | 
| tmpnam | tempnam |  |  | Create a name for a temporary file. | 
| ungetc |  |  |  | Push character back into input stream. | 
| vprintf | vfprintf | vsprintf |  | Print formatted output of a varargs argument list. |