R_IO(3)                    Library Functions Manual                    R_IO(3)

NAME
     r_io - Radare2 Input/Output Library API

SYNOPSIS
     #include <r_io.h>

DESCRIPTION
     The r_io library provides a unified interface for input/output operations
     in radare2, supporting various backends such as files, memory, network
     connections, and debuggers. It abstracts file descriptors, memory
     mappings, caching, and undo functionality.

     Key concepts:

     o   RIO is the main structure representing an I/O context.

     o   RIODesc represents an open file or resource descriptor.

     o   RIOMap defines memory mappings from file offsets to virtual
         addresses.

     o   RIOBank groups maps for banked memory architectures.

     o   Caching allows temporary modifications without altering the
         underlying data.

INITIALIZATION
     RIO * r_io_new(void)

     Creates and initializes a new I/O context.  void r_io_init(RIO *io)

     Initializes an existing I/O structure.  void r_io_free(RIO *io)

     Frees an I/O context and all associated resources.

FILE OPERATIONS
     RIODesc * r_io_open(RIO *io, const char *uri, int perm, int mode)

     Opens a resource specified by URI with given permissions and mode, and
     maps it at address 0.  RIODesc * r_io_open_at(RIO *io, const char *uri,
     int perm, int mode, ut64 at)

     Opens a resource and maps it at the specified address.  bool
     r_io_close(RIO *io)

     Closes the current descriptor.  bool r_io_read_at(RIO *io, ut64 addr, ut8
     *buf, int len)

     Reads len bytes from virtual address addr into buf.  bool
     r_io_write_at(RIO *io, ut64 addr, const ut8 *buf, int len)

     Writes len bytes from buf to virtual address addr.  ut64 r_io_seek(RIO
     *io, ut64 offset, int whence)

     Seeks to the specified offset. whence can be R_IO_SEEK_SET,
     R_IO_SEEK_CUR, or R_IO_SEEK_END.

MEMORY MAPPING
     RIOMap * r_io_map_add(RIO *io, int fd, int flags, ut64 delta, ut64 addr,
     ut64 size)

     Creates a new memory map from file descriptor fd at virtual address addr
     with size size, starting from file offset delta.  bool r_io_map_del(RIO
     *io, ut32 id)

     Deletes the map with the given id.  RIOMap * r_io_map_get(RIO *io, ut32
     id)

     Retrieves the map with the given id.  RIOMap * r_io_map_get_at(RIO *io,
     ut64 vaddr)

     Gets the map covering the virtual address vaddr.

BANKING
     RIOBank * r_io_bank_new(const char *name)

     Creates a new bank with the given name.  bool r_io_bank_add(RIO *io,
     RIOBank *bank)

     Adds a bank to the I/O context.  bool r_io_bank_use(RIO *io, ut32 bankid)

     Switches to the specified bank.

CACHING
     bool r_io_cache_write_at(RIO *io, ut64 addr, const ut8 *buf, int len)

     Writes to the cache at the specified address.  bool
     r_io_cache_read_at(RIO *io, ut64 addr, ut8 *buf, int len)

     Reads from the cache at the specified address.  void
     r_io_cache_commit(RIO *io, ut64 from, ut64 to, bool many)

     Commits cached changes to the underlying storage.

UNDO FUNCTIONALITY
     int r_io_undo_init(RIO *io)

     Initializes undo functionality.  void r_io_undo_enable(RIO *io, int seek,
     int write)

     Enables seek and/or write undo tracking.  void r_io_wundo_new(RIO *io,
     ut64 off, const ut8 *data, int len)

     Records a write operation for undo.

EXAMPLES
     Opening and reading a file:

     RIO *io = r_io_new();
     RIODesc *desc = r_io_open(io, "/bin/ls", R_PERM_R, 0);
     if (desc) {
         ut8 buf[64];
         r_io_read_at(io, 0, buf, sizeof(buf));
     }
     r_io_free(io);

     Creating a memory map:

     RIO *io = r_io_new();
     RIODesc *desc = r_io_open_nomap(io, "malloc://1024", R_PERM_RW, 0);
     if (desc) {
         RIOMap *map = r_io_map_add(io, desc->fd, R_PERM_RW, 0, 0x1000, 1024);
     }
     r_io_free(io);

     Using cache for temporary modifications:

     RIO *io = r_io_new();
     r_io_open(io, "file.bin", R_PERM_RW, 0);
     ut8 data[] = {0x90, 0x90}; // NOP NOP
     r_io_cache_write_at(io, 0x100, data, 2);
     // Changes are cached, not written to file yet
     r_io_cache_commit(io, 0x100, 0x102, false);
     // Now changes are committed
     r_io_free(io);

SEE ALSO
     r_core(3), r_bin(3), r_anal(3)

AUTHORS
     The radare2 project team.

Linux 6.19.10-arch1-1         September 20, 2025         Linux 6.19.10-arch1-1