src/file.S

@@ -66,8 +66,15 @@ cat_file:
 
 # Cat out stdin to stdout
 # @param[in] a0: Not used.
-# @param[out] a0: result code.
+# @param[out] a0: Not used.
 cat_stdin:
+    addi sp, sp, -16
+    sd ra, 0(sp)
+    sd s0, 8(sp)
+
+    la t1, show_ends
+    lb s0, 0(t1) # store if we show ends into s1
+
     .LReadStdinBlock:
     li a0, 0
     la a1, cat_buf
@@ -75,8 +82,15 @@ cat_stdin:
     li a7, 63
     ecall
     blez a0, .LCatStdinRet # if we haven't read any bytes, EOF, close FD
-    mv a2, a0 # move bytes read into bytes needed to write
 
+    beqz s0, .LNoEndingsStdinWrite
+    mv a1, a0
+    la a0, cat_buf
+    call _stdout_add_endings
+    j .LReadStdinBlock
+
+    .LNoEndingsStdinWrite:
+    mv a2, a0 # move bytes read into bytes needed to write
     li a0, 1
     la a1, cat_buf
     li a7, 64
@@ -84,6 +98,9 @@ cat_stdin:
     j .LReadStdinBlock
 
     .LCatStdinRet:
+    ld ra, 0(sp)
+    ld s0, 8(sp)
+    addi sp, sp, 16
     ret
 
 # Open fd

src/main.S

@@ -46,11 +46,12 @@ _start:
     call fetch_argc
     mv s0, a1 # store argc
     li s1, 1
+    li s2, 0 # processed files
     
     call _check_flags
 
     li t0, 1
-    ble s0, t0, .LProcessStdin # use stdin if no commands
+    ble s0, t0, .LProcessStdin # use stdin if no commands, although this is checked later, if no flags are used, we can go ahead and jump
     
     .LProcessFile:
     mv a0, s1
@@ -64,10 +65,12 @@ _start:
     ld a0, 0(sp)
     addi sp, sp, 8
     call cat_file
+    addi s2, s2, 1
     bnez a0, .LReturnFileErr # error if failed
     .LSkipArg:
     addi s1, s1, 1
     blt s1, s0, .LProcessFile
+    beqz s2, .LProcessStdin # if we reach the end of the file queue, and no files have actually been processed, that means they were all flags, switch to stdin
     j .LMainReturnOk
     
     .LProcessStdin: