Currently, Open sequence doesn't handle the case where magic_setflags and magic_load fails. We need to close magic and free the underlying resources.

Also, we must document that Close must be called once user is done with magic.

Just to note this solution somewhere in case someone else runs into it:

I was unable to compile the golang tool pistol on an M1 mac because homebrew installs files to /opt/homebrew/include† and /usr/local/include simply doesn't exist.
† or whatever your brew --prefix is set to.

❯ go install github.com/doronbehar/pistol/cmd/pistol@latest
# github.com/doronbehar/magicmime
Users/jonaustin/opt/_go/pkg/mod/github.com/doronbehar/[email protected]/magicmime.go:28:11: fatal error: 'magic.h' file not found
 #include <magic.h>
          ^~~~~~~~~
1 error generated.

Was able to fix this by simply symlinking things:

sudo ln -s /opt/homebrew/include /usr/local

I'm getting error "cannot open; magic mime db is already open"

Ubuntu 20.04 LTS
go version go1.18 linux/amd64

libmagic dependencies are probably not there, but worth giving it a try.

Remove /usr/local/lib from the paths to look for, it is already automatically included.

Hi,
I am installing magicmime via pistol and encounter this error on Macbook Air M1.

libmagic 5.45 (current latest) installed via brew. Has anyone the same issue? Should I downgrade libmagic on my machine? Thanks.

`
go install github.com/doronbehar/pistol/cmd/pistol@latest  !1/14
go: downloading github.com/doronbehar/pistol v0.4.2
go: downloading github.com/doronbehar/magicmime v0.1.1-0.20211127135329-3de4ff29dc49
go: downloading github.com/adrg/xdg v0.4.0
go: downloading github.com/alexflint/go-arg v1.4.3
go: downloading github.com/alessio/shellescape v1.4.1
go: downloading github.com/sirupsen/logrus v1.9.0
go: downloading github.com/alecthomas/chroma/v2 v2.7.0
go: downloading github.com/dustin/go-humanize v1.0.1
go: downloading github.com/mholt/archiver/v3 v3.5.1
go: downloading github.com/nwaples/rardecode v1.1.3
go: downloading github.com/alexflint/go-scalar v1.1.0
go: downloading golang.org/x/sys v0.7.0
go: downloading github.com/andybalholm/brotli v1.0.5
go: downloading github.com/dsnet/compress v0.0.2-0.20210315054119-f66993602bf5
go: downloading github.com/golang/snappy v0.0.4
go: downloading github.com/klauspost/compress v1.16.4
go: downloading github.com/klauspost/pgzip v1.2.5
go: downloading github.com/pierrec/lz4/v4 v4.1.17
go: downloading github.com/ulikunitz/xz v0.5.11
go: downloading github.com/xi2/xz v0.0.0-20171230120015-48954b6210f8
go: downloading github.com/dlclark/regexp2 v1.9.0

github.com/doronbehar/magicmime

ld: warning: ignoring file '/opt/homebrew/Cellar/libmagic/5.45/lib/libmagic.1.dylib': found architecture 'arm64', required architecture 'x86_64'
ld: Undefined symbols:
_magic_buffer, referenced from:
__cgo_31903eabb88b_Cfunc_magic_buffer in _x002.o
_magic_close, referenced from:
__cgo_31903eabb88b_Cfunc_magic_close in _x002.o
_magic_error, referenced from:
__cgo_31903eabb88b_Cfunc_magic_error in _x002.o
_magic_file, referenced from:
__cgo_31903eabb88b_Cfunc_magic_file in _x002.o
_magic_load, referenced from:
__cgo_31903eabb88b_Cfunc_magic_load in _x002.o
_magic_open, referenced from:
__cgo_31903eabb88b_Cfunc_magic_open in _x002.o
_magic_setflags, referenced from:
__cgo_31903eabb88b_Cfunc_magic_setflags in _x002.o
_magic_version, referenced from:
__cgo_31903eabb88b_Cfunc_magic_version in _x002.o
clang: error: linker command failed with exit code 1 (use -v to see invocation)
`

*** Error in `./app': free(): invalid next size (fast): 0x00007f79400b5140 ***

======= Backtrace: =========
/lib64/libc.so.6(+0x7c503)[0x7f7971af5503]
/usr/lib64/libmagic.so.1(file_vprintf+0x6c)[0x7f797247330c]
/usr/lib64/libmagic.so.1(file_printf+0x87)[0x7f79724733e7]
/usr/lib64/libmagic.so.1(file_trycdf+0x4c7)[0x7f7972477157]
/usr/lib64/libmagic.so.1(file_buffer+0x1c6)[0x7f7972473726]
/usr/lib64/libmagic.so.1(magic_buffer+0x31)[0x7f7972467b61]
./app(_cgo_f7c060554b06_Cfunc_magic_buffer+0x1f)[0x8093df]
./app[0x459c60]

I'm using magicmime with multiple goroutines but with a mutex around magicmime.TypeByBuffer(blob)

When I try to download this package using go get github.com/rakyll/magicmime I get an error saying

# github.com/rakyll/magicmime
../../rakyll/magicmime/magicmime.go:28:11: fatal error: 'magic.h' file not found
 #include <magic.h>
          ^
1 error generated.

What could be the possible reason for this error?

Hey @rakyll,

just wondering...

have you figured out a way to make it work with Travis?

I have tried with
henvic@d917cf8

but it doesn't work out
https://travis-ci.org/henvic/magicmime/builds/83209266

due to multiple definitions, but I don't get how it is happening. On my machine it works just fine.

here is code, on the TypeByBuffer call I get the panic:

       err := magicmime.Open(magicmime.MAGIC_MIME_TYPE)
       mime, err := magicmime.TypeByBuffer(buffer)
       if err != nil {
               return err
       }
       magicmime.Close()

fatal error: unexpected signal during runtime execution
Jun 05 07:36:23 : /usr/lib/golang/src/runtime/panic.go:503 +0x8e
Jun 05 07:36:23 : runtime.sigpanic()
Jun 05 07:36:23 : /usr/lib/golang/src/runtime/sigpanic_unix.go:14 +0x5e
Jun 05 07:36:23 : goroutine 6581214 [syscall, locked to thread]:
Jun 05 07:36:23 : runtime.cgocall_errno(0x401610, 0xc2080e1698, 0xc200000000)
Jun 05 07:36:23 : /usr/lib/golang/src/runtime/cgocall.go:130 +0xf5 fp=0xc2080e16
Jun 05 07:36:23 : github.com/rakyll/magicmime._Cfunc_magic_buffer(0x7fece80008c0
Jun 05 07:36:23 : github.com/rakyll/magicmime/_obj/_cgo_gotypes.go:76 +0x44 fp=0
Jun 05 07:36:23 : github.com/rakyll/magicmime.TypeByBuffer(0xc2085fda00, 0x200,
Jun 05 07:36:23 : /home/aa/go/src/github.com/rakyll/magicmime/magicmime.go:151

I'm getting a crash in libmagic when using this library with multiple goroutimes. I suspect the reason is because this library keeps a single global handle that is used for all libmagic calls. A quick google search tells me that libmagic handles cannot be shared across threads.

Perhaps a better way to deal with this would be to wrap the libmagic handle as an opaque object that is passed back to the caller from Open(). Close() would also need a receiver or take an opaque handle as an argument.

I am attempting to install Pistol, and I am running into an error involving magic mime.

doronbehar/pistol#76

The error states:

imports github.com/rakyll/magicmime: build constraints exclude all Go files in /home/user/go/bin/pkg/mod/github.com/rakyll/[email protected]

This is a new one for both me and the developer of pistol, and after doing some digging, an issue was discovered in the golang repository that mentions a potential solution to the issue by ensuring package main is used to denote the main script of the package.

golang/go#24068 (comment)

I attempted the suggested resolution, which created another error, because there is no main function in the source code.

So I am inquiring about a workaround that would allow me to use magicmime to install pistol.

• add instructions for brew
• cleanup inline docs and README

Hello @rakyll !

Is it possible to cut (semantic) version tags for magicmime? it would be easier to track it with dep.

Thank you for you work on the project.

The example in example_test.go has memeroy leak.

package main

import (
    "fmt"

    "github.com/rakyll/magicmime"
)

func main() {
    mm, err := magicmime.New(magicmime.MAGIC_MIME_TYPE | magicmime.MAGIC_SYMLINK | magicmime.MAGIC_ERROR)
    if err != nil {
        panic(err)
    }
   defer mm.Close()
    filepath := "/bin/ls"

    mimetype, err := mm.TypeByFile(filepath)
    if err != nil {
        fmt.Printf("Something went wrong: %s", err)
        return
    }

    fmt.Printf("%s -> %s\n", filepath, mimetype)
}

Take special attention for defer mm.Close()

Hi

I get cannot open; magic mime db is already open after my vscode crashed during tests and it obviously didn't close the db. However I cannot get it working again. If I ignore the error that it's already open, when I run magicmime.Close() I get invalid memory address or nil pointer dereference.

EDIT: this is still broken after rebooting

I can help with this but if somebody else have plenty of spare time, go get wild!