How to obtain application core dump from running process

To attach gdb to a running process run:

# gcore -a -o /tmp/<application>_core <pid>

An example:

# gcore -a -o /tmp/slapd_core $(pgrep -f slapd)

The result, in this case, is /tmp/slapd_core.27869.

It might be also interesting to share process/PID procfs details:

# [[ -e /tmp/<app>_proc.txt ]] && rm /tmp/<app>_proc.txt

# for i in $(cat << EOF
cmdline
environ
status
stat
wchan
stack
mounts
limits
io
smaps
maps
cgroup
EOF
); do
  { echo '## '$i; cat /proc/<pid>/$i; echo;} >> /tmp/<app>_proc.txt;
done

An example:

# [[ -e /tmp/slapd_proc.txt ]] && rm /tmp/slapd_proc.txt

# for i in $(cat << EOF
cmdline
environ
status
stat
wchan
stack
mounts
limits
io
smaps
maps
cgroup
EOF
); do
  { echo '## '$i; cat /proc/$(pgrep -f slapd)/$i; echo;} >> /tmp/slapd_proc.txt;
done

The results, in this case, is /tmp/slapd_proc.txt:

# head /tmp/attachment.txt 
/proc/27869/cmdline:slapd-F/tmp/test/slapd.d/-hldap://127.0.0.4:389 ldapi://%2ftmp%2fldapi-oslp=off-d1
/proc/27869/environ:LS_COLORS=no=00:fi=00:di=01;34:ln=00;36:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=41;33;01:ex=00;32:*.cmd=00;32:*.exe=01;32:*.com=01;32:*.bat=01;32:*.btm=01;32:*.dll=01;32:*.tar=00;31:*.tbz=00;31:*.tgz=00;31:*.rpm=00;31:*.deb=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.lzma=00;31:*.zip=00;31:*.zoo=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.tb2=00;31:*.tz2=00;31:*.tbz2=00;31:*.xz=00;31:*.avi=01;35:*.bmp=01;35:*.dl=01;35:*.fli=01;35:*.gif=01;35:*.gl=01;35:*.jpg=01;35:*.jpeg=01;35:*.mkv=01;35:*.mng=01;35:*.mov=01;35:*.mp4=01;35:*.mpg=01;35:*.pcx=01;35:*.pbm=01;35:*.pgm=01;35:*.png=01;35:*.ppm=01;35:*.svg=01;35:*.tga=01;35:*.tif=01;35:*.webm=01;35:*.webp=01;35:*.wmv=01;35:*.xbm=01;35:*.xcf=01;35:*.xpm=01;35:*.aiff=00;32:*.ape=00;32:*.au=00;32:*.flac=00;32:*.m4a=00;32:*.mid=00;32:*.mp3=00;32:*.mpc=00;32:*.ogg=00;32:*.voc=00;32:*.wav=00;32:*.wma=00;32:*.wv=00;32:HOSTTYPE=x86_64LESSCLOSE=lessclose.sh %s %sXKEYSYMDB=/usr/X11R6/lib/X11/XKeysymDBLANG=POSIXWINDOWMANAGER=/usr/bin/gnomeLESS=-M -I -RSUDO_GID=100GUESTFISH_RESTORE=\e[0mHOSTNAME=jb155sapqe01CSHEDIT=emacsGPG_TTY=/dev/pts/1LESS_ADVANCED_PREPROCESSOR=noCOLORTERM=1GUESTFISH_INIT=\e[1;34mSUDO_COMMAND=/bin/bashMACHTYPE=x86_64-suse-linuxMINICOM=-c onQT_SYSTEM_DIR=/usr/share/desktop-dataOSTYPE=linuxUSER=rootPAGER=lessGUESTFISH_PS1=\[\e[1;32m\]><fs>\[\e[0;31m\] MORE=-slPWD=/tmpHOME=/rootLC_CTYPE=en_US.UTF-8HOST=jb155sapqe01SUDO_USER=slesXNLSPATH=/usr/X11R6/lib/X11/nlsXDG_DATA_DIRS=/usr/local/share:/usr/sharePROFILEREAD=trueSUDO_UID=1000FROM_HEADER=MAIL=/var/mail/rootLESSKEY=/etc/lesskey.binSHELL=/bin/bashTERM=xtermLS_OPTIONS=-A -N --color=tty -T 0XCURSOR_THEME=DMZSHLVL=1MANPATH=/usr/share/man:/usr/local/man:/usr/local/share/manLOGNAME=rootJRE_HOME=/usr/lib64/jvm/java-21-openjdk-21XDG_CONFIG_DIRS=/etc/xdgPATH=/sbin:/usr/sbin:/usr/local/sbin:/root/bin:/usr/local/bin:/usr/bin:/bin:/usr/lib/mit/binGUESTFISH_OUTPUT=\e[0mG_BROKEN_FILENAMES=1HISTSIZE=1000CPU=x86_64LESSOPEN=lessopen.sh %s_=/usr/sbin/slapdOLDPWD=/root
/proc/27869/status:Name:        slapd
/proc/27869/status:Umask:       0022
/proc/27869/status:State:       S (sleeping)
/proc/27869/status:Tgid:        27869
/proc/27869/status:Ngid:        0
/proc/27869/status:Pid: 27869
/proc/27869/status:PPid:        22184
/proc/27869/status:TracerPid:   0