BusyBox combines tiny versions of many common UNIX utilities into a single small executable.

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12
votes
4answers
4k views

How does one atomically change a symlink to a directory in busybox?

I am trying to (as close as possibly) atomically change a symlink. I've tried: ln -sf other_dir existing_symlink That just put the new symlink in the directory that existing_symlink pointed to. ln ...
9
votes
3answers
10k views

How do I check busybox version (from busybox)?

I'm using busybox in a embedded system, and I would like to check its version. How do I check the busybox version from within busybox?
8
votes
2answers
102k views

Recovering from 'grub rescue>' crash [closed]

Originally posted to AskUbuntu.com ... AskUbuntu has adopted a policy of closing questions about EOL (End Of Life) versions. There's a vocal contingent to remove them as well. To prevent ...
8
votes
3answers
4k views

Wake-on-LAN with BusyBox?

Is it possible to implement the wake-on-lan magic packet in bash? I'm using a old, customized BusyBox and don't have ether-wake. Is it possible to replace it with some other shell command, like: ...
8
votes
4answers
10k views

when does the system send a SIGTERM to a process?

My server program received a SIGTERM and stopped (with exit code 0). I am surprised by this, as I am pretty sure that there was plenty of memory for it. Under what conditions does linux (busybox) send ...
7
votes
3answers
1k views

Generate new name for moved file to prevent overwriting?

How can I generate a new name for a file if there's an existing file With that same name? In a Desktop environment a new name is generated my appending a number to the end of the file name, but how ...
7
votes
2answers
2k views

What overwrites /etc/resolv.conf on every boot?

I was given the files for a mini linux, that boots directly into firefox. It works for all it should be doing, only that I do not get an internet connection. We have 3 DNS servers in the network, ...
7
votes
2answers
721 views

Which sed version is not GNU sed 4.0?

I'm trying to figure out which version of sed that I've got on BusyBox 1.18.3. The --version output is cryptic. $ sed --version This is not GNU sed version 4.0 The following code is from the ...
6
votes
1answer
637 views

inittab '-' character in process field

I have a an inittab file with the following entry: console::askfirst:-/bin/ash According to this Man page a '+' character in the process field means init will not do utmp and wtmp accounting ...
6
votes
2answers
986 views

How to develop a small linux distro?

Since Linux uses open-source packages, I was wondering if I could develop my own Linux distro by compiling these packages. I tried to read the Linux From Scratch book but it's quite big and uses lots ...
6
votes
1answer
10k views

Create and control start up scripts in BusyBox

I have compiled a custom linux kernel in BusyBox. BusyBox init does not support runlevels. When the kernel boots up in BusyBox, it first executes init which looks for the specified runlevel in ...
5
votes
3answers
4k views

How to generate initramfs image with busybox links?

Having been directed to initramfs by an answer to my earlier question (thanks!), I've been working on getting initramfs working. I can now boot the kernel and drop to a shell prompt, where I can ...
5
votes
2answers
3k views

How to get 3 minutes future date?

I want to get the date 3 minutes on the future. For example, if "now" is 01-Jan-70 00:00:00 GMT I want to get 01-Jan-80 00:03:00 GMT How should I do it? I'm working with busybox linux.
5
votes
1answer
2k views

Search for a string in files recursively in BusyBox 1.0? [duplicate]

Possible Duplicate: How to grep a text recursively on BusyBox 1.0? How can I search for a string in a file recursively in BusyBox 1.0 if find and grep are not available ? (I want to telnet ...
5
votes
1answer
2k views

updating `/etc/resolv.conf` on a read only filesystem

I currently have a busybox based embedded linux system. The filesystem is a readonly mounted jffs2 filesystem. One problem I've run into is that /etc/resolv.conf can't be updated by DHCP. Is it ...
5
votes
3answers
208 views

sshd not starting after boot on embedded linux built with buildroot?

I've done a minimal install using buildroot's default config for the Raspberry Pi. I also selected openssh and openssl from menuconfig: Package Selection for the target ---> [*] Networking ...
5
votes
1answer
299 views

Using OGG/Vorbis, is there a way to continue to record to an existing audio file?

I am using Vorbis/ogg to record audio (using arecord and then pipping to oggenc). I have downloaded oggvideotools, which gave me oggCat, which will let me join two previously recorded audio files into ...
4
votes
3answers
345 views

RegExp testing with ash shell (BusyBox)

I need to do a RegExp pattern test on a certain bit of user input. This is the pattern I need to test the value against. ^([a-z]{2,3})\-([a-z][a-z]*[0-9]*)\-(\d+)$ An example match would be: ...
4
votes
2answers
9k views

Trouble getting busybox switch_root to work

I'm working on an embedded ARM Linux system that boots using initramfs. (Here's some background from a couple earlier questions, if you're interested.) So far, thanks in part to help received here, I ...
4
votes
3answers
1k views

How to get whole command line from a process?

How can I get the command arguments or the whole command line from a running process using its process name? For example this process: # ps PID USER TIME COMMAND 1452 root 0:00 ...
4
votes
2answers
650 views

How do I find the resident memory size of a process on busybox?

I run top on busybox and it shows all processes and their virtual memory size. How do I determine how much RAM is being used by each process?
4
votes
1answer
2k views

Minimal Linux with kernel and BusyBox: /etc/inittab is ignored, only /init is executed

I managed to create a small and fully functional live Linux CD which contains only kernel (compiled with default options) and BusyBox (compiled with default options + static, all applets present, ...
4
votes
1answer
1k views

Rename files with spaces in a BusyBox shell

I'm trying to rename some files on my Synology Diskstation via SSH. The available shell is the BusyBox built-in shell: BusyBox v1.16.1 (2013-04-16 20:13:10 CST) built-in shell (ash) The move ...
3
votes
5answers
15k views

Bash iterate over a list of strings

I have this bash script: for opt in string1 string2 string3 ... string99 do somestuff It works, but I would like to replace the explicit listing of my strings with a file which actually contains ...
3
votes
6answers
6k views

Trying to set date on a Linux based machine from another machine

I am running busy box on an embedded platform. I would like to set the date on the box properly each time I reboot the hardware. I have no way to save the time persistently, so am reduced to setting ...
3
votes
4answers
255 views

How can I reboot my Linux system every 60 seconds?

I am debugging some embedded hardware that runs Linux 3.2.6 Angstrom distro, I need the unit to reboot every 60 seconds. I tried this: In /etc/rc5.d : S99reboot -> /home/root/test.sh ...
3
votes
2answers
6k views

Sorting by date

Original: Jan 23 2011 10:42 SOMETHING 2007.12.20.avi Jun 26 2009 SOMETHING 2009.06.25.avi Feb 12 2010 SOMETHING 2010.02.11.avi Jan 29 2011 09:17 SOMETHING 2011.01.27.avi Feb 11 2011 20:06 SOMETHING ...
3
votes
2answers
42 views

Reason for BusyBox environment in debian-installer?

Debian-installer main menu has an "Execute a shell" option which starts an ash(Almquist shell) in BusyBox environment. One can exit this environment back to debian-installer with the exit command. ...
3
votes
2answers
948 views

Remove 50GB oldest files in busybox when used capacity reaches 95%

Ok i have requested a code here but initial i didn't ask to make it busybox compatible. My bad. I'm new to linux and coding. The code needs to do the following: Delete 50GB of oldest data (dir ...
3
votes
1answer
354 views

What is the complementary command to 'rx' for xmodem transfer?

I have an installation of busybox on an embedded linux system that comes with a great little utility called rx: rx FILE Receive a file using the xmodem protocol This is perfect for transferring ...
3
votes
1answer
3k views

What are special prompt symbols for busybox's sh support?

I want to setup a time prompt on PS1. But, there is no document about what are symbols the busybox support. Is there any one know? Here are all which I knew. PS1='\u@\h: \w \$'
3
votes
3answers
702 views

Script matching literal pattern over multiple lines?

I have a multi-line string in the variable $PAT. $PAT must be searched for within the file $FILE. If $PAT is in $FILE, it needs to print the file with $PAT removed. If $PAT is not found, then print ...
3
votes
3answers
695 views

How to remove a trailing CRLF from a file?

I have a binary file with a trailing CRLF (2 bytes total) that I want to remove. How should I do it? Please note that I'm using busybox and I don't have perl.
3
votes
1answer
1k views

How to custom build debian's busybox?

I'm building an embedded system based on debian 7, and I'd like to make the most out of busybox that comes with debian. The problem is default busybox build in debian seems quite minimal, for example ...
3
votes
1answer
255 views

ls pagination on MontaVista with BusyBox

I'm logged into an IP Phone running MontaVista with a very stripped down BusyBox binary (by stripped down, I mean the OEM has removed almost all of its functionality, except the basics like cat, ls ...
3
votes
2answers
4k views

What does ifup do when “/etc/network/interfaces” has an invalid netmask address?

The interfaces file looks like below: auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 192.168.0.130 netmask 250.255.255.0 gateway 192.168.0.254 As you can see ...
3
votes
1answer
804 views

Need to improve urlencode function

I need a way to URL encode strings with a shell script on a OpenWRT device running old version of busybox. Right now I ended up with the following code: urlencode() { echo "$@" | awk -v ORS="" '{ ...
3
votes
1answer
3k views

How to grep a text recursively on BusyBox 1.0?

How can I find a file containing a certain string on a BusyBox 1.0, if grep -r does not work?
3
votes
2answers
388 views

shell howto: save multiple binary data files (jpg) to one file with some additional data and separate again

I have a system with restricted calculational power (fritzbox) and functions (busybox) and an webcam, able to deliver JPG files. Now I'm looking for for a method (based on shell script) to download ...
3
votes
2answers
90 views

What is stopping our UDP packets (how does it know the route is down)?

We have a server (camera) sending RTSP video packets via UDP. At a customer site it travels over several hops, one of which may be an unreliable WiFi link that drops the odd packet or five. Usually ...
3
votes
1answer
2k views

Unable to use busybox implementation of hwclock

I have a buildroot generated kernel (3.6.11) and root file system running on an x86 device. It uses busybox and I am trying to set the BIOS hardware clock using hwclock. I get this error whenever I ...
3
votes
2answers
879 views

How can I get the GNU screen command to automatically start with every BusyBox ash session?

On an embedded device with BusyBox installed I want to set it up so that the gnu screen command is automatically started when any BusyBox session is started. I have seen that I can add the screen ...
3
votes
1answer
1k views

How to enter into BusyBox when booting?

I have occasionally installed cloud-init package in Ubuntu, which blocks me from booting. Neither recovery mode works. Because cloud-init installed some upstart job configuration. So I want to enter ...
3
votes
1answer
381 views

Busybox NAS appliance

I have a NAS appliance that crashed last weekend. The IT guys apparently / maybe didn't recover it in the right way? There's about 50,000 directories in a "lost+found" directory each with a numeric ...
3
votes
3answers
13k views

How to remount as read-write a specific mount of device?

How to remount as read-write a specific mount of device? (one folder) The file is "Read-only file system", rw-r-r, so it not allow to change permissions. I need to replace that file, then change ...
3
votes
0answers
622 views

Number comparisons in BusyBox ash

I have the following script that extracts data from the EXIF command on my BusyBox ash-based system. I parse the date tag from the end of the file and use case as a final check to ensure the format ...
2
votes
1answer
527 views

Regex doesn't work with grep

I have a string like this TEST="/dev/sda1 on /media/sda1 type vfat (rw,relatime,fmask=0000,dmask=0000,allow_utime=0022,codepage=cp437,iocharset=iso8859-1,quiet)" (Result from mount | grep sda1) ...
2
votes
1answer
3k views

Chaining commands within `watch`

Ok, this is driving me a bit nuts. I'm trying to watch the number of files in a set of subdirectories. find . | wc -l correctly returns the number of sub-folders and files. However, watch 'find . | ...
2
votes
2answers
900 views

No /proc in a Busybox-based embedded Linux distribution

I am making an embedded Linux distribution and my board is a Raspberry Pi. My kernel version is 3.2.27 without initramfs and my root file system as follows: /lib /* contains ...
2
votes
1answer
7k views

how to make read only filesystem writable on busybox?

I want to change some files on my router. Firstly i can change everything in /var, but i want to change /etc/fstab. when i try to change it, i get an error message that says filesystem is read only. ...