The ELF file exists in / usr / bin, but it turns out "-ash: file: not found"

Question

I am trying to install some new software package under openwrt using opkg, and the installation was successful, and we see that the binary really exists in / usr / bin, and I have a reader, the same thing. as below:

root@OpenWrt /usr/bin [#]# opkg files cfdisk Package cfdisk (2.25.2-4) is installed on root and has the following files: /usr/sbin/cfdisk root@OpenWrt /usr/bin [#]# ls /usr/sbin/ adjtimex arping ethtool iptables-save mkfs.ext3 pppd telnetd airbase-ng besside-ng fdisk iw mkfs.ext4 rate.awk uhttpd aireplay-ng brctl hostapd iwconfig modinfo rmmod wpa_supplicant airmon-ng cfdisk insmod iwlist modprobe samba_multicall wpad airmon-zc chroot ip6tables iwpriv nmbd smbd xtables-multi airodump-ng crond ip6tables-restore lsmod ntpclient smbpasswd airodump-ng-oui-update dnsmasq ip6tables-save miniupnpd ntpd swapoff airserv-ng dropbear iptables mke2fs odhcp6c swapon airtun-ng e2fsck iptables-restore mkfs.ext2 pdnsd tc root@OpenWrt /usr/bin [#]# cfdisk -ash: cfdisk: not found root@OpenWrt /usr/bin [#]# ./cfdisk -ash: ./cfdisk: not found root@OpenWrt /usr/bin [#]# ldd cfdisk -ash: cfdisk: not found root@OpenWrt /usr/bin [#]# ldd id libcrypt.so.0 => /lib/libcrypt.so.0 (0x77898000) libm.so.0 => /lib/libm.so.0 (0x77872000) libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x7784e000) libc.so.0 => /lib/libc.so.0 (0x777e2000) ld-uClibc.so.0 => /lib/ld-uClibc.so.0 (0x778bc000) root@OpenWrt /usr/bin [#]# export export HOME='/root' export LOGNAME='root' export OLDPWD='/usr' export PATH='/usr/bin:/usr/sbin:/bin:/sbin' export PS1='\[\033[35;1m\]\u\[\033[0m\]@\[\033[31;1m\]\h \[\033[32;1m\]$PWD\[\033[0m\] [\[\033[35m\]\#\[\033[0m\]]\[\033[31m\]\$\[\033[0m\] ' export PWD='/usr/bin' export SHELL='/bin/ash' export SHLVL='1' export SSH_CONNECTION='192.168.1.152 29105 192.168.1.1 22' export SSH_TTY='/dev/pts/0' export TERM='xterm' export USER='root' root@OpenWrt /usr/bin [#]# 

thanks.

Answer 1

As @nos mentioned in the comments on the question, this can happen if the binary is linked to libc that does not exist on your device.

eg. This is the result that I get when I try to run a binary file that was created with the wrong libc (note that I specify the full path /usr/bin/ldd , because without this, for some reason, I got the same error " not found "which you mark in your question).

 root@OpenWrt :~# /usr/bin/ldd badbin ldd: can't open cache '/etc/ld.so.cache' checking sub-depends for '/usr/lib/libusb-1.0.so.0' checking sub-depends for '/lib/libgcc_s.so.1' checking sub-depends for 'not found' libusb-1.0.so.0 => /usr/lib/libusb-1.0.so.0 (0x00000000) libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00000000) libc.so => not found (0x00000000) not a dynamic executable 

For me, the problem was that I was creating my package using the wrong toolchain. I assumed that the repo git://git.openwrt.org/openwrt.git was for Chaos Calmer (current release at the time of writing). But, of course, a repo is a branch of development (svn trunk). I needed to use git://git.openwrt.org/15.05/openwrt.git .

You can confirm which libc you are creating by checking the toolchain staging_dir directory name. The libc version is the last component of the name (e.g. toolchain-mips_34kc+dsp_gcc-4.8-linaro_uClibc-0.9.33.2 uses uClibc-0.9.33.2).

Compare this version with the version of libc that is present on your router by checking that /lib/libc.so* refers to your router (run ls -l /lib/libc.so* ). If you need to change the libc version used by your toolchain, then make menuconfig in buildroot OpenWRT and install the libc version in Advanced configuration options (for developers) Toolchain Options C Library implementation . You probably won’t need to change this setting, but make sure that you are building from the correct source repo for the version installed on your router.