1	#!/usr/bin/env bash
2	#
3	# Test call stack introspection. There are a bunch of special variables
4	# defined here:
5	#
6	# https://www.gnu.org/software/bash/manual/html_node/Bash-Variables.html
7	#
8	# - The shell function ${FUNCNAME[$i]} is defined in the file
9	# ${BASH_SOURCE[$i]} and called from ${BASH_SOURCE[$i+1]}
10	#
11	# - ${BASH_LINENO[$i]} is the line number in the source file
12	# (${BASH_SOURCE[$i+1]}) where ${FUNCNAME[$i]} was called (or
13	# ${BASH_LINENO[$i-1]} if referenced within another shell function).
14	#
15	# - For instance, ${FUNCNAME[$i]} was called from the file
16	# ${BASH_SOURCE[$i+1]} at line number ${BASH_LINENO[$i]}. The caller builtin
17	# displays the current call stack using this information.
18	#
19	# So ${BASH_SOURCE[@]} doesn't line up with ${BASH_LINENO}. But
20	# ${BASH_SOURCE[0]} does line up with $LINENO!
21	#
22	# Geez.
23
24
25	#### ${FUNCNAME[@]} array
26	g() {
27	argv.py "${FUNCNAME[@]}"
28	}
29	f() {
30	argv.py "${FUNCNAME[@]}"
31	g
32	argv.py "${FUNCNAME[@]}"
33	}
34	f
35	## STDOUT:
36	['f']
37	['g', 'f']
38	['f']
39	## END
40
41	#### FUNCNAME with source
42	f() {
43	. spec/testdata/echo-funcname.sh
44	}
45	g() {
46	f
47	}
48	g
49	. spec/testdata/echo-funcname.sh
50	argv.py "${FUNCNAME[@]}"
51	## STDOUT:
52	['source', 'f', 'g']
53	['source']
54	[]
55	## END
56
57	#### ${BASH_SOURCE[@]} is a stack of source files for function calls
58	$SH spec/testdata/bash-source.sh
59	## STDOUT:
60	['begin F funcs', 'f', 'main']
61	['begin F files', 'spec/testdata/bash-source.sh', 'spec/testdata/bash-source.sh']
62	['begin F lines', '21', '0']
63	['G funcs', 'g', 'f', 'main']
64	['G files', 'spec/testdata/bash-source-2.sh', 'spec/testdata/bash-source.sh', 'spec/testdata/bash-source.sh']
65	['G lines', '15', '21', '0']
66	['end F funcs', 'f', 'main']
67	['end F', 'spec/testdata/bash-source.sh', 'spec/testdata/bash-source.sh']
68	['end F lines', '21', '0']
69	## END
70
71	#### ${BASH_LINENO[@]} is a stack of line numbers for function calls
72	# note: it's CALLS, not DEFINITIONS.
73	g() {
74	argv.py G "${BASH_LINENO[@]}"
75	}
76	f() {
77	argv.py 'begin F' "${BASH_LINENO[@]}"
78	g # line 6
79	argv.py 'end F' "${BASH_LINENO[@]}"
80	}
81	f # line 9
82	## STDOUT:
83	['begin F', '9']
84	['G', '6', '9']
85	['end F', '9']
86	## END
87
88	#### $LINENO is the current line, not line of function call
89	g() {
90	argv.py $LINENO # line 2
91	}
92	f() {
93	argv.py $LINENO # line 5
94	g
95	argv.py $LINENO # line 7
96	}
97	f
98	## STDOUT:
99	['5']
100	['2']
101	['7']
102	## END
103