[SOLVED] Why is pkg-config not found for some shell substitutions in shell?

Issue

I tried several commands in zsh:

# 1 work
echo `pkg-config --version`
# 2 work
echo $(pkg-config --version)

# 3 not work: pkg-config command not found
echo `pkg‑config ‑‑cflags ‑‑libs glib‑2.0`
# 4 work
echo $(pkg-config --cflags --libs glib-2.0)

# 5 not work: pkg-config command not found
gcc $(pkg‑config ‑‑cflags ‑‑libs glib‑2.0) ‑o test test.c
# 6 work
gcc test.c ‑o test $(pkg‑config ‑‑cflags ‑‑libs glib‑2.0) 

# 7 not work: pkg-config command not found
gcc `pkg‑config ‑‑cflags ‑‑libs glib‑2.0` ‑o test test.c
# 8 work
gcc test.c ‑o test `pkg‑config ‑‑cflags ‑‑libs glib‑2.0`

Why does no.3 not work while no.4 can? Why do I have to put the shell constitution at the end for gcc (no. 4-8)? Is it caused by my shell settings?

Solution

I think you may need to check the dash -. (not ‑)

# 3 not work: pkg-config command not found
echo `pkg‑config ‑‑cflags ‑‑libs glib‑2.0`
#        ^ here  ^^       ^^         ^  and these


# 4 work
echo $(pkg-config --cflags --libs glib-2.0)
#         ^ This one is the correct one.

Answered By - ktc

Answer Checked By - Marilyn (WPSolving Volunteer)