bash file cannot find /dev/sdb

jsalk · 2016-01-13 19:01:05

I am trying to use a bash file to partition /dev/sdb. When I enter "fdisk /dev/sdb" in a terminal, I have no problem. But I would like to automate this function using the following bash file:

#!/bin/bash
# partition the drive
sed -e 's/\t\([\+0-9a-zA-Z]*\)[ \t].*/\1/' << EOF | fdisk /dev/sdb
  o # clear the in memory partition table
  n # new partition
  p # primary partition
  1 # partition number 1
    # default - start at beginning of disk 
    # default - end at end of disk
  p # print the in-memory partition table
  w # write the partition table
EOF

Running "/bin/bash /var/www/shell/drive-partition.sh" from a terminal command prompt, I get this result:

Welcome to fdisk (util-linux 2.27.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

: No such file or directory

Running it in a web page using "exec('/bin/bash /var/www/shell/drive-partition.sh 2>&1', $retArr, $retVal);" in a php file, I get this output:

fdisk: cannot open /dev/sdb : No such file or directory
1
finished

I'm curious as to why fdisk can find /dev/sdb when running directly and cannot in a bash file. Any ideas would be appreciated.

- Jim

Trilby · 2016-01-13 19:06:13

jsalk wrote:

I'm curious as to why fdisk can find /dev/sdb when running directly and cannot in a bash file.

You just showed that it can, just the commands entered don't work.

You did show that /dev/sdb is not accessible from a php script. This is not particularly surprising to me.

jsalk · 2016-01-13 19:36:31

Trilby wrote:

jsalk wrote:
I'm curious as to why fdisk can find /dev/sdb when running directly and cannot in a bash file.
You just showed that it can, just the commands entered don't work.
You did show that /dev/sdb is not accessible from a php script. This is not particularly surprising to me.

Thanks.

It seems to me that I also showed that it is not currently accessible from a bash script. The problem is, I have to use one to enter all the fdisk commands.

Some time ago, I saw a system that formatted a drive via a web script (I wish I could recall where it was). So I would think it is possible. I just don't know why the bash script cannot find the drive.

- Jim

Slithery · 2016-01-13 21:31:10

As you've discovered fdisk doesn't like being run from a script. That's the job of sfdisk (scriptable fdisk).

man sfdisk

Last edited by Slithery (2016-01-14 17:49:15)

Arch Linux

#1 2016-01-13 19:01:05

bash file cannot find /dev/sdb

#2 2016-01-13 19:06:13

Re: bash file cannot find /dev/sdb

#3 2016-01-13 19:36:31

Re: bash file cannot find /dev/sdb

#4 2016-01-13 21:31:10

Re: bash file cannot find /dev/sdb

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