src/nash/nash.8

   1 .TH NASH 8 "Sat Mar 27 1999"
   2 .UC 4
   3 .SH NAME
   4 nash \- script interpretor to interpret linuxrc images
   5 .SH SYNOPSIS
   6 \fBnash\fR [--quiet] [--force] \fIscript\fR
   7
   8 .SH DESCRIPTION
   9 \fBnash\fR is a very simple script interpretor designed to be as small as
  10 possible. It is primarily designed to run simple linuxrc scripts on an initrd
  11 image. Arguments to commands may be enclosed in either single or double
  12 quotes to allow spaces to be included in the arguments. Spaces outside of
  13 quotations always delineate arguments, and so backslash escaping is supported.
  14
  15 Additionally, if nash is invoked as \fBmodprobe\fR, it will immediately
  16 exit with a return code of zero. This is to allow initrd's to prevent some
  17 extraneous kernel error messages during startup.
  18
  19 There are two types of commands, built in and external. External commands
  20 are run from the filesystem via execve(). If commands names are given without
  21 a path, nash will search it's builtin PATH, which is /usr/bin, /bin,
  22 /sbin, /usr/sbin.
  23
  24 Currently, \fBnash\fR supports the following built in commands.
  25
  26 .TP
  27 \fBaccess -[r][w][x][f] \fIpath\fR
  28 Tells whether the current user has sufficient permissions to read, write, or
  29 execture \fIpath\fR, or if the file exists (see \fBaccess(2)\fR for more
  30 information).
  31
  32 .TP
  33 \fBecho [item]* [> \fIfilename\fR]\fR
  34 Echos the text strings given to a file, with a space in between each
  35 item. The output may be optionally redirected to a file.
  36
  37 \fBexec\fR \fI<command>\fR
  38 The command given is execed, overlaying the nash process.
  39
  40 .TP
  41 \fBfind \fIdir\fR -name \fIname\fR
  42 Display the path to files named \fIname\fR in or below directory \fIdir\FR.
  43 This is a \fBvery\fR limited implementation of find(1).
  44
  45 .TP
  46 \fBfindlodev\fR
  47 Prints the full path to the first unused loopback block device on the
  48 system. If none is available, no output is displayed.
  49
  50 .TP
  51 \fBlosetup \fI/dev/loopdev\fR \fIfile\fR
  52 Binds \fIfile\fR to the loopback device \fI/dev/loopdev\fR. See
  53 \fBlosetup(8)\fR for information on loopback devices.
  54
  55 .TP
  56 \fBmkdevices\fR \fIpath\fR
  57 Creates device files for all of the block devices listed in
  58 \fB/proc/partitions\fR in the directory specfied by \fIpath\fR.
  59
  60 .TP
  61 \fBmkdir\fR \fI[-p]\fR \fIpath\fR
  62 Creates the directory \fIpath\fR. If \fI-p\fR is specified, this command
  63 will not complain if the directory exists. Note this is a subset of the
  64 standard \fBmkdir\fR \fI-p\fR behavior.
  65
  66 .TP
  67 \fBmknod\fR \fIpath\fR \fI[c|b]\fR \fImajor\fR \fIminor\fR
  68 Creates a device inode for \fIpath\fR. This is identical to \fBmkdev\fR(1)
  69 which the exceptions that it will not create named pipes and if the directories
  70 in \fIpath\fR do not exist they will be automatically created.
  71
  72 .TP
  73 \fBmkrootdev \fIpath\fR
  74 Makes \fIpath\fR a block inode for the device which should be mounted
  75 as root. To determine this device nash uses
  76 the device suggested by the root= kernel command line argument (if
  77 root=LABEL is used devices are probed to find one with that label). If
  78 no root= argument is available, /proc/sys/kernel/real-root-dev provides
  79 the device number.
  80
  81 .TP
  82 \fBmount \fI[--ro]\fR -o \fIopts\fR -t \fItype\fR \fIdevice\fR \fImntpoint\fR
  83 Mounts a filesystem. It does not support NFS, and it must be used in
  84 the form given above (arguments must go first).  If \fIdevice\fR is of the form
  85 \fBLABEL=\fIfoo\fR the devices listed in /fB/proc/partitions\fR will
  86 be searched, and the first device with a volume label of \fIfoo\fR will
  87 be mounted. Normal \fBmount\fR(2) options are supported, and \fB--ro\fR will
  88 mount the filesystem read only for compatibility with older versions of nash.
  89 The \fBdefaults\fR mount option is silently ignored.
  90
  91 .TP
  92 \fBpivot_root \fInewrootpath\fR \fIoldrootpath\fR
  93 Makes the filesystem mounted at \fInewrootpath\fR the new root filesystem,
  94 and mounts the current root filesystem as \fIoldrootpath\fR.
  95
  96 .TP
  97 \fBraidautorun \fImddevice\fR
  98 Runs raid autodetection on all raid-typed partitions. \fImddevice\fR must
  99 be a raid device (any will do).
 100
 101 .TP
 102 \fBshowlabels\fR
 103 Display a table of devices, their filesystem labels, and their uuids.
 104
 105 .TP
 106 \fBumount \fIpath\fR
 107 Unmounts the filesystem mounted at \fIpath\fR.
 108
 109 .SH RETURN VALUE
 110 Returns 0 is the last command succeeded or 1 if it failed.
 111
 112 .SH OPTIONS
 113 .TP
 114 \fB-\-force\fR
 115 Allows \fBforce\fR really execute the script, even though \fBnash\fR doesn't
 116 appear to be running from an initrd image.
 117
 118 .SH BUGS
 119 Probably many. \fBnash\fR is \fbnot a shell\fR, and it shouldn't be thought of
 120 as one. It isn't entirely different from a shell, but that's mostly by
 121 accident.
 122
 123 .SH AUTHOR
 124 .nf
 125 Erik Troan <ewt@redhat.com>
 126 .fi