examples/nsh ^^^^^^^^^^^^ This directory contains the NuttShell (NSH). This is a simple shell application for NuttX. - Console/NSH Front End - Command Overview - Conditional Command Execution - Built-In Variables - Current Working Directory Environment Variables: - Simple Commands - NSH Configuration Settings Command Dependencies on Configuration Settings NSH-Specific Configuration Settings Console/NSH Front End ^^^^^^^^^^^^^^^^^^^^^ Using settings in the configuration file, NSH may be configured to use either the serial stdin/out or a telnet connection as the console or BOTH. When NSH is started, you will see the following welcome on either console: NuttShell (NSH) nsh> 'nsh>' is the NSH prompt and indicates that you may enter a command from the console. Command Overview ^^^^^^^^^^^^^^^^ This directory contains the NuttShell (NSH). This is a simple shell-like application. At present, NSH supports the following commands forms: Simple command: Command with re-directed output: > >> Background command: & Re-directed background command: > & >> & Where: is any one of the simple commands listed later. is the full or relative path to any writable object in the filesystem name space (file or character driver). Such objects will be referred to simply as files throughout this README. NSH executes at the mid-priority (128). Backgrounded commands can be made to execute at higher or lower priorities using nice: [nice [-d >]] [> |>> ] [&] Where is any value between -20 and 19 where lower (more negative values) correspond to higher priorities. The default niceness is 10. Conditional Command Execution ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ An if-then[-else]-fi construct is also supported in order to support conditional execution of commands. This works from the command line but is primarily intended for use within NSH scripts (see the sh commnd). The syntax is as follows: if then [sequence of ] else [sequence of ] fi Built-In Variables ^^^^^^^^^^^^^^^^^^ $? - The result of the last simple command execution Current Working Directory ^^^^^^^^^^^^^^^^^^^^^^^^^ All path arguments to commands may be either an absolute path or a path relative to the current working directory. The current working directory is set using the 'cd' command and can be queried either by using the 'pwd' command or by using the 'echo $PWD' command. Environment Variables: ---------------------- PWD - The current working directory OLDPWD - The previous working directory Simple Commands ^^^^^^^^^^^^^^^ o [ ] o test These are two alternative forms of the same command. They support evaluation of a boolean expression which sets $?. This command is used most frequently as the conditional command following the 'if' in the if-then[-else]-fi construct. Expression Syntax: ------------------ expression = simple-expression | !expression | expression -o expression | expression -a expression simple-expression = unary-expression | binary-expression unary-expression = string-unary | file-unary string-unary = -n string | -z string file-unary = -b file | -c file | -d file | -e file | -f file | -r file | -s file | -w file binary-expression = string-binary | numeric-binary string-binary = string = string | string == string | string != string numeric-binary = integer -eq integer | integer -ge integer | integer -gt integer | integer -le integer | integer -lt integer | integer -ne integer o cat [ [ ...]] This command copies and concatentates all of the files at to the console (or to another file if the output is redirected). o cd [|-|~|..] Changes the current working directory (PWD). Also sets the previous working directory environment variable (OLDPWD). FORMS: ------ 'cd ' sets the current working directory to . 'cd -' sets the current working directory to the previous working directory ($OLDPWD). Equivalent to 'cd $OLDPWD'. 'cd' or 'cd ~' set the current working directory to the 'home' directory. The 'home' directory can be configured by setting CONFIG_LIB_HOMEDIR in the configuration file. The default 'home' directory is '/'. 'cd ..' sets the current working directory to the parent directory. o cp

Copy of the contents of the file at to the location in the filesystem indicated by o echo [ [...]] Copy the sequence of strings and expanded environment variables to console out (or to a file if the output is re-directed). o exec Execute the user logic at address . NSH will pause until the execution unless the user logic is executed in background via 'exec &' o exit Exit NSH. Only useful if you have started some other tasks (perhaps using the 'exec' command') and you would like to have NSH out of the way. o get [-b|-n] [-f ] -h

Copy the file at from the host whose IP address is identified by . Other options: -f The file will be saved relative to the current working directory unless is provided. -b|-n Selects either binary ("octect") or test ("netascii") transfer mode. Default: text. o help Presents summary information about each command to console. o ifconfig Show the current configuration of the network, for example: nsh> ifconfig eth0 HWaddr 00:18:11:80:10:06 IPaddr:10.0.0.2 DRaddr:10.0.0.1 Mask:255.255.255.0 if uIP statistics are enabled (CONFIG_NET_STATISTICS), then this command will also show the detailed state of uIP. o ls [-lRs] Show the contents of the directory at . NOTE: must refer to a directory and no other filesystem object. Options: -------- -R Show the constents of specified directory and all of its sub-directories. -s Show the size of the files along with the filenames in the listing -l Show size and mode information along with the filenames in the listing. o mb [=][ ] o mh [=][ ] o mw [=][ ] Access memory using byte size access (mb), 16-bit accesses (mh), or 32-bit access (mw). In each case, . Specifies the address to be accessed. The current value at that address will always be read and displayed. =. Read the value, then write to the location. . Perform the mb, mh, or mw operation on a total of bytes, increment the appropriately after each access Example nsh> mh 0 16 0 = 0x0c1e 2 = 0x0100 4 = 0x0c1e 6 = 0x0110 8 = 0x0c1e a = 0x0120 c = 0x0c1e e = 0x0130 10 = 0x0c1e 12 = 0x0140 14 = 0x0c1e nsh> o mem Show the current state of the memory allocator. For example, nsh> mem arena: fe2560 ordblks: 1 mxordblk: fdc3e0 uordblks: 6180 fordblks: fdc3e0 nsh> Where: arena - This is the total size of memory allocated for use by malloc in bytes. ordblks - This is the number of free (not in use) chunks. mxordblk - Size of the largest free (not in use) chunk uordblks - This is the total size of memory occupied by chunks handed out by malloc. fordblks - This is the total size of memory occupied by free (not in use) chunks. o mkdir Create the directory at . All components of of except the final directory name must exist on a mounted file system; the final directory must not. Recall that NuttX uses a pseudo filesystem for its root file system. The mkdir command can only be used to create directories in volumes set up with the mount command; it cannot be used to create directories in the pseudo filesystem. Example: ^^^^^^^^ nsh> mkdir /mnt/fs/tmp nsh> ls -l /mnt/fs /mnt/fs: drw-rw-rw- 0 TESTDIR/ drw-rw-rw- 0 TMP/ nsh> o mkfatfs Format a fat file system on the block device specified by path. NSH provides this command to access the mkfatfs() NuttX API. This block device must reside in the NuttX psuedo filesystem and must have been created by some call to register_blockdriver() (see include/nuttx/fs.h). o mkfifo Creates a FIFO character device anywhere in the pseudo file system, creating whatever psuedo directories that may be needed to complete the full path. By convention, however, device drivers are place in the standard /dev directory. After it is created, the FIFO device may be used as any other device driver. NSH provides this command to access the mkfifo() NuttX API. Example: ^^^^^^^^ nsh> ls -l /dev /dev: crw-rw-rw- 0 console crw-rw-rw- 0 null brw-rw-rw- 0 ram0 nsh> mkfifo /dev/fifo nsh> ls -l /dev ls -l /dev /dev: crw-rw-rw- 0 console crw-rw-rw- 0 fifo crw-rw-rw- 0 null brw-rw-rw- 0 ram0 nsh> o mount -t

The 'mount' command mounts a file system in the NuttX psuedo filesystem. 'mount' performs a three way associating, binding File system. The '-t ' option identifies the type of file system that has been formatted on the . As of this writing, vfat is the only supported value for Block Device. The argument is the full or relative path to a block driver inode in the psuedo filesystem. By convention, this is a name under the /dev sub-directory. This must have been previously formatted with the same file system type as specified by Mount Point. The mount point is the location in the psuedo file system where the mounted volume will appear. This mount point can only reside in the NuttX psuedo filesystem. By convention, this mount point is a subdirectory under /mnt. The mount command will create whatever psuedo directories that may be needed to complete the full path but the full path must not already exist. After the the volume has been mounted in the NuttX psuedo file system, it may be access in the same way as other objects in the file system. Example: ^^^^^^^^ nsh> ls -l /dev /dev: crw-rw-rw- 0 console crw-rw-rw- 0 null brw-rw-rw- 0 ram0 nsh> ls /mnt nsh: ls: no such directory: /mnt nsh> mount -t vfat /dev/ram0 /mnt/fs nsh> ls -l /mnt/fs/testdir /mnt/fs/testdir: -rw-rw-rw- 15 TESTFILE.TXT nsh> echo "This is a test" >/mnt/fs/testdir/example.txt nsh> ls -l /mnt/fs/testdir /mnt/fs/testdir: -rw-rw-rw- 15 TESTFILE.TXT -rw-rw-rw- 16 EXAMPLE.TXT nsh> cat /mnt/fs/testdir/example.txt This is a test nsh> o ps Show the currently active threads and tasks. For example, nsh> ps PID PRI SCHD TYPE NP STATE NAME 0 0 FIFO TASK READY Idle Task() 1 128 RR TASK RUNNING init() 2 128 FIFO TASK WAITSEM nsh_telnetmain() 3 100 RR PTHREAD WAITSEM (21) nsh> o ping [-c ] [-i ] Test the network communication with a remote peer. Example, nsh> 10.0.0.1 PING 10.0.0.1 56 bytes of data 56 bytes from 10.0.0.1: icmp_seq=1 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=2 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=3 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=4 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=5 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=6 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=7 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=8 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=9 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=10 time=0 ms 10 packets transmitted, 10 received, 0% packet loss, time 10190 ms nsh> o put [-b|-n] [-f ] -h

Copy the file at to the host whose IP address is identified by . Other options: -f The file will be saved with the same name on the host unless unless is provided. -b|-n Selects either binary ("octect") or test ("netascii") transfer mode. Default: text. o pwd Show the current working directory. nsh> cd /dev nsh> pwd /dev nsh> Same as 'echo $PWD' nsh> echo $PWD /dev nsh> o rm Remove the specified name from the mounted file system. Recall that NuttX uses a pseudo filesystem for its root file system. The rm command can only be used to remove (unlink) files in volumes set up with the mount command; it cannot be used to remove names from the pseudo filesystem. Example: ^^^^^^^^ nsh> ls /mnt/fs/testdir /mnt/fs/testdir: TESTFILE.TXT EXAMPLE.TXT nsh> rm /mnt/fs/testdir/example.txt nsh> ls /mnt/fs/testdir /mnt/fs/testdir: TESTFILE.TXT nsh> o rmdir Remove the specified directory from the mounted file system. Recall that NuttX uses a pseudo filesystem for its root file system. The rmdir command can only be used to remove directories from volumes set up with the mount command; it cannot be used to remove directories from the pseudo filesystem. Example: ^^^^^^^^ nsh> mkdir /mnt/fs/tmp nsh> ls -l /mnt/fs /mnt/fs: drw-rw-rw- 0 TESTDIR/ drw-rw-rw- 0 TMP/ nsh> rmdir /mnt/fs/tmp nsh> ls -l /mnt/fs ls -l /mnt/fs /mnt/fs: drw-rw-rw- 0 TESTDIR/ nsh> o set Set the environment variable to the sting . For example, nsh> echo $foobar nsh> set foobar foovalue nsh> echo $foobar foovalue nsh> o sh Execute the sequence of NSH commands in the file referred to by . o sleep Pause execution (sleep) of seconds. o unset Remove the value associated with the environment variable . Example: nsh> echo $foobar foovalue nsh> unset foobar nsh> echo $foobar nsh> o usleep Pause execution (sleep) of microseconds. NSH Configuration Settings ^^^^^^^^^^^^^^^^^^^^^^^^^^ The availability of the above commands depends upon features that may or may not be enabled in the NuttX configuration file. The following table indicates the dependency of each command on NuttX configuration settings. General configuration settings are discussed in the NuttX Porting Guide. Configuration settings specific to NSH as discussed at the bottom of this README file. Command Dependencies on Configuration Settings ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Command Depends on Configuration ---------- -------------------------- [ !CONFIG_EXAMPLES_NSH_DISABLESCRIPT cat CONFIG_NFILE_DESCRIPTORS > 0 cd !CONFIG_DISABLE_ENVIRON && CONFIG_NFILE_DESCRIPTORS > 0 cp CONFIG_NFILE_DESCRIPTORS > 0 echo -- exec -- exit -- get CONFIG_NET && CONFIG_NET_UDP && CONFIG_NFILE_DESCRIPTORS > 0 help -- ifconfig CONFIG_NET ls CONFIG_NFILE_DESCRIPTORS > 0 mb,mh,mw --- mem --- mkdir !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 mkfatfs !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT mkfifo !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 mount !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT ping CONFIG_NET && CONFIG_NET_ICMP && CONFIG_NET_ICMP_PING && !CONFIG_DISABLE_CLOCK && !CONFIG_DISABLE_SIGNALS ps -- put CONFIG_NET && CONFIG_NET_UDP && CONFIG_NFILE_DESCRIPTORS > 0 pwd !CONFIG_DISABLE_ENVIRON && CONFIG_NFILE_DESCRIPTORS > 0 rm !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 rmdir !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 set !CONFIG_DISABLE_ENVIRON sh CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NFILE_STREAMS > 0 && !CONFIG_EXAMPLES_NSH_DISABLESCRIPT sleep !CONFIG_DISABLE_SIGNALS test !CONFIG_EXAMPLES_NSH_DISABLESCRIPT umount !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT unset !CONFIG_DISABLE_ENVIRON usleep !CONFIG_DISABLE_SIGNALS NSH-Specific Configuration Settings ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The behavior of NSH can be modified with the following settings in the configs//defconfig file: * CONFIG_EXAMPLES_NSH_FILEIOSIZE Size of a static I/O buffer used for file access (ignored if there is no filesystem). * CONFIG_EXAMPLES_NSH_STRERROR strerror(errno) makes more readable output but strerror() is very large and will not be used unless this setting is 'y' * CONFIG_EXAMPLES_NSH_LINELEN The maximum length of one command line and of one output line. Default: 80 * CONFIG_EXAMPLES_NSH_STACKSIZE The stack size to use when spawning new threads or tasks. Such new threads are generated when a command is executed in background or as new TELNET connections are established. * CONFIG_EXAMPLES_NSH_NESTDEPTH The maximum number of nested if-then[-else]-fi sequences that are permissable. Default: 3 * CONFIG_EXAMPLES_NSH_DISABLESCRIPT This can be set to 'y' to suppress support for scripting. This setting disables the 'sh', 'test', and '[' commands and the if-then[-else]-fi construct. This would only be set on systems where a minimal footprint is a necessity and scripting is not. * CONFIG_EXAMPLES_NSH_DISABLEBG This can be set to 'y' to suppress support for background commands. This setting disables the 'nice' command prefix and the '&' command suffix. This would only be set on systems where a minimal footprint is a necessity and background command execution is not. * CONFIG_EXAMPLES_NSH_CONSOLE If CONFIG_EXAMPLES_NSH_CONSOLE is set to 'y', then a serial console front-end is selected. * CONFIG_EXAMPLES_NSH_TELNET If CONFIG_EXAMPLES_NSH_TELNET is set to 'y', then a TELENET server front-end is selected. When this option is provided, you may log into NuttX remotely using telnet in order to access NSH. One or both of CONFIG_EXAMPLES_NSH_CONSOLE and CONFIG_EXAMPLES_NSH_TELNET must be defined. If CONFIG_EXAMPLES_NSH_TELNET is selected, then there some other configuration settings that apply: * CONFIG_EXAMPLES_NSH_IOBUFFER_SIZE Determines the size of the I/O buffer to use for sending/ receiving TELNET commands/reponses * CONFIG_EXAMPLES_NSH_DHCPC Obtain the the IP address via DHCP. * CONFIG_EXAMPLES_NSH_IPADDR If CONFIG_EXAMPLES_NSH_DHCPC is NOT set, then the static IP address must be provided. * CONFIG_EXAMPLES_NSH_DRIPADDR Default router IP address * CONFIG_EXAMPLES_NSH_NETMASK Network mask * CONFIG_EXAMPLES_NSH_NOMAC Set if your ethernet hardware has no built-in MAC address. If set, a bogus MAC will be assigned.