perror(): Print unknown errors too with errno

console.asm

@@ -11,6 +11,7 @@ section .rodata
 
 	; Errors (perror)
 	perrorMsg	db	"%s: %s",10,0
+	perrorInvalid	db	"%s: Unknown error (errno %d)",10,0
 	errorMsgs	dq	em0,em1,em2,em3,em4,em5,em6,em7,em8,em9,em10,em11,em12,em13,em14,em15,em16,em17,em18,em19,em20,em21,em22,em23,em24,em25,em26,em27,em28,em29,em30,em31,em32,em33,em34
 	em0		db	"No error",0
 	em1		db	"Operation not permitted",0
@@ -263,12 +264,18 @@ perror:
 	jge	.quit
 	neg	rax
 	cmp	rax, 34
-	jg	.quit
+	jg	.unknown
 	mov	rsi, rdi
 	lea	rdi, [rel perrorMsg]
 	lea	rdx, [errorMsgs + rax*8]
 	mov	rdx, [rdx]
 	call	printf
+	jmp	.quit
+	.unknown:
+	mov	rsi, rdi
+	lea	rdi, [rel perrorInvalid]
+	mov	rdx, rax
+	call	printf
 	.quit:
 	pop	rax
 	ret

tests.asm

@@ -91,6 +91,7 @@ section	.rodata
 	msgPerror1	db	"TEST perror(",34,"ErrTest",34,") (rax=0):",NL,EOS
 	msgPerror2	db	"TEST perror(",34,"ErrTest",34,") (rax=-22):",NL,EOS
 	msgPerror3	db	"TEST perror(",34,"ErrTest",34,") (rax=7):",NL,EOS
+	msgPerror4	db	"TEST perror(",34,"ErrTest",34,") (rax=-50)",NL,EOS
 	perrorStr	db	"ErrTest",EOS
 	; min() / minu()
 	msgMin		db	NL,"# min() / minu()",EOS
@@ -282,6 +283,13 @@ _start:
 	mov	rax, 7
 	lea	rdi, [rel perrorStr]
 	call	perror
+
+	; TEST: perror (err=-50)
+	lea	rdi, [rel msgPerror4]
+	call	print
+	mov	rax, -50
+	lea	rdi, [rel perrorStr]
+	call	perror
 %ENDIF
 %IF TEST_min
 	lea	rdi, [rel msgMin]