# File.read unexpected error **URL:** \ **Category:** Help & Support\ **Created:** [May 20, 2024, 2:10pm UTC](https://forum.crystal-lang.org/t/file-read-unexpected-error/6855 "2024-05-20T14:10:21Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![robmullr](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/robmullr/32/1113_2.png) [@robmullr](https://forum.crystal-lang.org/u/robmullr)\ **Post date:** [May 20, 2024, 2:10pm UTC](https://forum.crystal-lang.org/t/file-read-unexpected-error/6855/1 "2024-05-20T14:10:21Z")
I’ve got a C header file (testfile.h) that only has a comment line "/\* comment _/". When I execute “puts File.read(testfile.h)” an error is generated: 1 | /_ comment \*/ ^ Error: invalid regex: quantifier does not follow a repeatable item at 0 Using Crystal 1.12.1 on x86\_64-pc-windows-msvc This is not expected behavior, shouldn’t it simply read the characters and return the string? If I wanted regex processing, I’d tell it to. Any explanation or work around appreciated. ---
**Author:** ![beta-ziliani](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/beta-ziliani/32/1821_2.png) [@beta-ziliani](https://forum.crystal-lang.org/u/beta-ziliani)\ **Post date:** [May 20, 2024, 3:54pm UTC](https://forum.crystal-lang.org/t/file-read-unexpected-error/6855/2 "2024-05-20T15:54:59Z")
Just to be sure, you have a file `testfile.h` with ```c /* comment / ``` And another file, say `test.cr`, with ```cr puts File.read("testfile.h") ``` and you execute `crystal test.cr` and it fails? ---
**Author:** ![robmullr](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/robmullr/32/1113_2.png) [@robmullr](https://forum.crystal-lang.org/u/robmullr)\ **Post date:** [May 20, 2024, 5:35pm UTC](https://forum.crystal-lang.org/t/file-read-unexpected-error/6855/3 "2024-05-20T17:35:54Z")
Hmm, that case didn’t work earlier but now it does. I’ve recreated the issue using an ARGV[0] input. The test.cr file is one line: `puts File.read(ARGV[0])` and is in the same directory as the testfile.h. When executed using `crystal run test.cr testfile.h` it responds with the invalid regex error. ---
**Author:** ![straight-shoota](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/straight-shoota/32/36_2.png) [@straight-shoota](https://forum.crystal-lang.org/u/straight-shoota)\ **Post date:** [May 20, 2024, 6:42pm UTC](https://forum.crystal-lang.org/t/file-read-unexpected-error/6855/4 "2024-05-20T18:42:33Z")
When you pass multiple paths to `crystal run` they are all treated as source files. So the compiler tries to read `testfile.h` as Crystal code (which it is not). If you want to pass options to the compiled program, you need to separate them with `--`: `crystal run test.cr -- testfile.h`