I have googled "procps" and tried lots of methods to install the package for several hours, but either errors or warnings got. I am so stupid
$ make install
gcc -c -D_GNU_SOURCE -I proc -I/usr/include/ncurses -fno-common -ffast-math -W -Wall -Wshadow -Wcast-align -Wredundant-decls -Wbad-function-cast -Wcast-qual -Wwrite-strings -Waggregate-return -Wstrict-prototypes -Wmissing-prototypes -O2 -s -DSHARED=1 -fpic proc/escape.c -o proc/escape.o
proc/escape.c:1: warning: -fpic ignored for target (all code is position independent)
In file included from proc/readproc.h:14,
from proc/escape.h:7,
from proc/escape.c:15:
proc/pwcache.h:12: error: syntax error before "uid"
proc/pwcache.h:12: warning: function declaration isn't a prototype
proc/pwcache.h:13: error: syntax error before "gid"
proc/pwcache.h:13: warning: function declaration isn't a prototype
In file included from proc/escape.h:7,
from proc/escape.c:15:
proc/readproc.h:164: error: syntax error before "uid_t"
proc/readproc.h:164: warning: no semicolon at end of struct or union
proc/readproc.h:172: error: syntax error before '}' token
proc/readproc.h:172: warning: type defaults to `int' in declaration of `PROCTAB'
proc/readproc.h:172: warning: data definition has no type or storage class
proc/readproc.h:175: error: syntax error before '*' token
proc/readproc.h:175: warning: declaration of 'flags' shadows a global declaration
proc/readproc.h:167: warning: shadowed declaration is here
proc/readproc.h:175: warning: type defaults to `int' in declaration of `openproc'
proc/readproc.h:175: warning: data definition has no type or storage class
proc/readproc.h:186: error: syntax error before "PROCTAB"
proc/readproc.h:186: warning: function declaration isn't a prototype
proc/readproc.h:193: warning: declaration of 'flags' shadows a global declaration
proc/readproc.h:167: warning: shadowed declaration is here
proc/readproc.h:196: error: syntax error before '*' token
proc/readproc.h:196: warning: function declaration isn't a prototype
proc/readproc.h:199: error: syntax error before '*' token
proc/readproc.h:199: warning: function declaration isn't a prototype
proc/readproc.h:200: error: syntax error before '*' token
proc/readproc.h:200: warning: function declaration isn't a prototype
In file included from proc/escape.c:15:
proc/escape.h:19: warning: declaration of 'flags' shadows a global declaration
proc/readproc.h:167: warning: shadowed declaration is here
proc/escape.c: In function `escape_strlist':
proc/escape.c:163: warning: declaration of 'i' shadows a global declaration
proc/readproc.h:166: warning: shadowed declaration is here
proc/escape.c: At top level:
proc/escape.c:179: warning: declaration of 'flags' shadows a global declaration
proc/readproc.h:167: warning: shadowed declaration is here
make: *** [proc/escape.o] Error 1