in npx dash-wasm: after the cat command, subsequent commands have problems with stdout
martin12333 opened this issue · comments
(a probably related issue: #42 )
// error when I used dash-wasm that was installed by npm
cd ~/10-cowasm/node_modules/dash-wasm
npx dash-wasm -x
(cowasm)$ cat wrongname1
+ cat wrongname1
cat: wrongname1: No such file or directory
(cowasm)$ cat wrongname1
+ cat wrongname1
cat: wrongname1: No such file or directory
cat: stdout: Bad file descriptor
(cowasm)$ cat /cowasm/usr/share/termcap
+ cat /cowasm/usr/share/termcap
cat: stdout: Bad file descriptor
(cowasm)$ echo abc
+ echo abc
sh: 4: echo: echo: I/O error
(cowasm)$ python
+ python
Python 3.11.0 (main, Nov 29 2022, 20:26:05) [Clang 15.0.3 (git@github.com:ziglang/zig-bootstrap.git 0ce789d0f7a4d89fdc4d9571 on wasi
Type "help", "copyright", "credits" or "license" for more information.
# i cannot see what i am typing
# 78*89
# aaaaaaaaa
# quit()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OSError: [Errno 8] Bad file descriptor
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name 'aaaaaaaaa' is not defined
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>
OSError: [Errno 8] Bad file descriptor
(cowasm)$
(in browser, commands work correctly)
(but with 1 extra error message)
EDIT I have cut this chapter into a comment
(in a built dash, and using only the cat from the tar package, no errors)
EDIT I have cut this chapter into a comment
LATER: bin/cat from fs.zip ... errors even when I bypassed dash-wasm ... when I ran it from npx kernel dash
in a comment
LATER: the built ./cat from the tar package ... works ok even when I ran it from npx dash-wasm
in a comment
(in browser, commands work correctly)
(but with 1 extra error message)
(cowasm)$ cat wrongname1
cat: wrongname1: No such file or directory
(cowasm)$ cat wrongname1
cat: wrongname1: No such file or directory
cat: stdout: Bad file descriptor
(cowasm)$ echo skfjdsf
skfjdsf
(cowasm)$ echo $PATH
/usr/bin:.
(cowasm)$ python
Python 3.11.0 (main, Nov 29 2022, 20:26:05) [Clang 15.0.3 (git@github.com:ziglang/zig-bootstrap.git 0ce789d0f7a4d89fdc4d9571 on wasi
Type "help", "copyright", "credits" or "license" for more information.
>>> fhgfh
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name 'fhgfh' is not defined
(in a built dash, and using only the cat from the tar package, no errors)
I have built only dash and the tar package (contains also cpio and cat).
EDIT
I don't mean that there were something wrong with the npm version. ... I am still not sure how I should run a built dash correctly. I am still studying.
...
git clone ...
cd ...
make
...
cd ~/cowasm/
./bin/dash-wasm-raw -ex
# maybe a better invocation is something like
npx kernel dash
# note: but /cowasm does not exist
cd packages
cd tar
cd dist
cd wasm
cd bin
ls -l
./cat wrongname1
...
The problem might just be that I haven't finished implementing all error handling paths in dash.
The original dash uses setjmp/longjmp for error handling. However, those don't exist in WASM (except via the not-pretty asyncify), so I'm basically rewriting dash to not use them by instead passing back error codes. I did this in some cases, but not everywhere yet. Fortunately, the source code of dash is relatively easy to understand :-). If you know C, and want to help with this, I can give you some pointers.
(Cowasm is BSD licensed, so your contributions are to a fully open source project. I'm having to take a break for a bit from very active cowasm development to catch up on a bunch of other things.)
Ok, I will just now add the remaining 2 mentioned experiments ... for completeness, and then I will read your comment again.
LATER: bin/cat from fs.zip ... errors even when I bypassed dash-wasm ... when I ran it from npx kernel dash
(
https://github.com/sagemathinc/cowasm/blob/main/packages/coreutils/src/utils/cat/cat.c#L98
)
// 2023-01 BTW, cat.c contains
(fclose(stdout))
cd ~/10-cowasm/node_modules/dash-wasm
npx kernel ./node_modules/@cowasm/dash/dist/wasm/bin/dash -x
ls /cowasm
# /usr/bin/ls: cannot access '/cowasm': No such file or directory
cd dist
zipinfo fs.zip
zipinfo fs.zip |grep cat
unzip fs.zip bin/cat
bin/cat skdjfslkfj
bin/cat 1
cat 1
echo sdfjskf
bin/cat ~/cowasm/R*
(cowasm)$ bin/cat skdjfslkfj
+ bin/cat skdjfslkfj
cat: skdjfslkfj: No such file or directory
(cowasm)$ bin/cat skdjfslkfj
+ bin/cat skdjfslkfj
cat: skdjfslkfj: No such file or directory
(cowasm)$ bin/cat 1
+ bin/cat 1
cat: stdout: Bad file descriptor
(cowasm)$ cat 1
+ cat 1
/usr/bin/cat: write error: Bad file descriptor
(cowasm)$
(cowasm)$ echo sdfjskf
+ echo sdfjskf
dash: 7: echo: echo: I/O error
(cowasm)$
LATER: the built ./cat from the tar package ... works ok even when I ran it from npx dash-wasm
(https://github.com/libarchive/libarchive/blob/master/cat/bsdcat.c)
// BTW, I didn't find there anything like fclose(stdout)
cd ~/10-cowasm/node_modules/dash-wasm
npx
npx dash-wasm -x
cd ~/cowasm
cd packages
cd tar
cd dist
cd wasm
cd bin
ls -l
./cat wrongname1
##./cat cat # BINARY
##./cat cat
####./cat cat # problems with my terminal ... so i restarted ... ... eventually the entire WSL
./cat ~/cowasm/R*
./cat ~/cowasm/R*
# OK
I suspected, that after the end of the cat (wasm), the stdout of the parent shell (the dash in wasm) maybe is in the closed(?) state.
Experiment:
cd ~/10-cowasm/node_modules/dash-wasm
npx dash-wasm -x
python
import os, sys
os.fstat(1)
quit()
os.stat_result(st_mode=8640, st_ino=3, st_dev=98, st_nlink=1, st_uid=0, st_gid=0, st_size=0, st_atime=1673941490, st_mtime=1673941488, st_ctime=1673880218)
cat anyname1
cat anyname1
echo abc
python
import os, sys
x=os.fstat(1)
print(x, file=sys.stderr)
os.stat_result(st_mode=8640, st_ino=0, st_dev=0, st_nlink=1, st_uid=0, st_gid=0, st_size=0, st_atime=1673941624, st_mtime=1673941624, st_ctime=1673941624)
I plan to learn how to use the DEBUG env var ... https://www.npmjs.com/package/debug