The Linux proc(5) man page tells me that /proc/$pid/mem “can be used to access the pages of a process's memory”. But a straightforward attempt to use it only gives me

$ cat /proc/$$/mem /proc/self/mem cat: /proc/3065/mem: No such process cat: /proc/self/mem: Input/output error 

Why didn't these work? How can I read from /proc/$pid/mem? And what is this strange “no such process” error (3065 is the PID of my shell)?

The Linux proc(5) man page tells me that /proc/$pid/mem “can be used to access the pages of a process's memory”. But a straightforward attempt to use it only gives me

$ cat /proc/$$/mem /proc/self/mem cat: /proc/3065/mem: No such process cat: /proc/self/mem: Input/output error 

Why isn't cat able to print its own memory (/proc/self/mem)? And what is this strange “no such process” error when I try to print the shell's memory (/proc/$$/mem, obviously the process exists)? How can I read from /proc/$pid/mem, then?

The Linux proc(5) man page tells me that /proc/$pid/mem “can be used to access the pages of a process's memory”. But a straightforward attempt to use it only gives me

$ cat /proc/$$/mem /proc/self/mem cat: /proc/3065/mem: No such process cat: /proc/self/mem: Input/output error 

Why didn't these work? How can I read from /proc/$pid/self? And what is this strange “no such process” error (3065 is the PID of my shell)?

The Linux proc(5) man page tells me that /proc/$pid/mem “can be used to access the pages of a process's memory”. But a straightforward attempt to use it only gives me

$ cat /proc/$$/mem /proc/self/mem cat: /proc/3065/mem: No such process cat: /proc/self/mem: Input/output error 

Why didn't these work? How can I read from /proc/$pid/mem? And what is this strange “no such process” error (3065 is the PID of my shell)?