1NASH(8) System Manager's Manual NASH(8)
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6 nash - script interpretor to interpret linuxrc images
7
9 nash [--quiet] [--force] script
10
13 nash is a very simple script interpretor designed to be as small as
14 possible. It is primarily designed to run simple linuxrc scripts on an
15 initrd image. Arguments to commands may be enclosed in either single or
16 double quotes to allow spaces to be included in the arguments. Spaces
17 outside of quotations always delineate arguments, and so backslash
18 escaping is supported.
19 Additionally, if nash is invoked as modprobe, it will immediately exit
21 with a return code of zero. This is to allow initrd's to prevent some
22 extraneous kernel error messages during startup.
23 There are two types of commands, built in and external. External com‐
25 mands are run from the filesystem via execve(). If commands names are
26 given without a path, nash will search it's builtin PATH, which is
27 /usr/bin, /bin, /sbin, /usr/sbin.
28 Currently, nash supports the following built in commands.
30 access -[r][w][x][f] path
33 Tells whether the current user has sufficient permissions to
34 read, write, or execture path, or if the file exists (see
35 access(2) for more information).
36 echo [item]* [> filename]
39 Echos the text strings given to a file, with a space in between
40 each item. The output may be optionally redirected to a file.
41 exec <command> The command given is execed, overlaying the nash
43 process.
44 find dir -name name
47 Display the path to files named name in or below directory dir.
48 This is a very limited implementation of find(1).
49 losetup /dev/loopdev file
52 Binds file to the loopback device /dev/loopdev. See losetup(8)
53 for information on loopback devices.
54 mkdevices path
57 Creates device files for all of the block devices listed in
58 /proc/partitions in the directory specfied by path.
59 mkdir [-p] path
62 Creates the directory path. If -p is specified, this command
63 will not complain if the directory exists. Note this is a subset
64 of the standard mkdir -p behavior.
65 mknod path [c|b] major minor
68 Creates a device inode for path. This is identical to mkdev(1)
69 which the exceptions that it will not create named pipes and if
70 the directories in path do not exist they will be automatically
71 created.
72 mkdmnod
75 Creates a device inode for the device mapper control inode as
76 /dev/mapper/control. If it already exists with the correct
77 major/minor, it will not be recreated.
78 mkrootdev path
81 Makes path a block inode for the device which should be mounted
82 as root. To determine this device nash uses the device suggested
83 by the root= kernel command line argument (if root=LABEL is used
84 devices are probed to find one with that label). If no root=
85 argument is available, /proc/sys/kernel/real-root-dev provides
86 the device number.
87 mount [--ro] -o opts -t type device mntpoint
90 Mounts a filesystem. It does not support NFS, and it must be
91 used in the form given above (arguments must go first). If
92 device is of the form LABEL=foo the devices listed in
93 /fB/proc/partitions will be searched, and the first device with
94 a volume label of foo will be mounted. Normal mount(2) options
95 are supported, and --ro will mount the filesystem read only for
96 compatibility with older versions of nash. The defaults mount
97 option is silently ignored.
98 pivot_root newrootpath oldrootpath
101 Makes the filesystem mounted at newrootpath the new root
102 filesystem, and mounts the current root filesystem as oldroot‐
103 path.
104 readlink path
107 Displays the value of the symbolic link path.
108 raidautorun mddevice
111 Runs raid autodetection on all raid-typed partitions. mddevice
112 must be a raid device (any will do).
113 setquiet
116 Cause any later echos in this script to not be displayed.
117 showlabels
120 Display a table of devices, their filesystem labels, and their
121 uuids.
122 sleep num
125 Sleep for num seconds
126 switchroot newrootpath
129 Makes the filesystem mounted at newrootpath the new root
130 filesystem by moving the mountpoint. This will only work in 2.6
131 or later kernels.
132 umount path
135 Unmounts the filesystem mounted at path.
136
139 Returns 0 is the last command succeeded or 1 if it failed.
140
143 --force
144 Allows force really execute the script, even though nash doesn't
145 appear to be running from an initrd image.
146
149 Probably many. nash is not a shell, and it shouldn't be thought of as
150 one. It isn't entirely different from a shell, but that's mostly by
151 accident.
152 Mon Aug 02 2004 NASH(8)