I installed Cygwin64 and tried its pgrep.exe tool (with admin privilege) as follows:
PS D:\cygwin64\bin> D:\cygwin64\bin\pgrep.exe svchost.exe
PS D:\cygwin64\bin> D:\cygwin64\bin\pgrep.exe svchost.exe -af
PS D:\cygwin64\bin> D:\cygwin64\bin\pgrep.exe -h
Usage:
pgrep [options] <pattern>
Options:
-d, --delimiter <string> specify output delimiter
-l, --list-name list PID and process name
-a, --list-full list PID and full command line
-v, --inverse negates the matching
-w, --lightweight list all TID
-c, --count count of matching processes
-f, --full use full process name to match
-g, --pgroup <PGID,...> match listed process group IDs
-G, --group <GID,...> match real group IDs
-i, --ignore-case match case insensitively
-n, --newest select most recently started
-o, --oldest select least recently started
-O, --older <seconds> select where older than seconds
-P, --parent <PPID,...> match only child processes of the given parent
-s, --session <SID,...> match session IDs
-t, --terminal <tty,...> match by controlling terminal
-u, --euid <ID,...> match by effective IDs
-U, --uid <ID,...> match by real IDs
-x, --exact match exactly with the command name
-F, --pidfile <file> read PIDs from file
-L, --logpidfile fail if PID file is not locked
-r, --runstates <state> match runstates [D,S,Z,...]
-A, --ignore-ancestors exclude our ancestors from results
--cgroup <grp,...> match by cgroup v2 names
--ns <PID> match the processes that belong to the same
namespace as <pid>
--nslist <ns,...> list which namespaces will be considered for
the --ns option.
Available namespaces: ipc, mnt, net, pid, user, uts
-h, --help display this help and exit
-V, --version output version information and exit
For more details see pgrep(1).
PS D:\cygwin64\bin>
Seems pgrep.exe is running correctly but it fails to return the pid of svchost.exe.
