Cross-Platform Script Line Endings

Script File Line Endings

Script files are among the most sensitive to incorrect line endings. A bash script with CRLF endings won't execute on Unix, and a batch file with LF endings may malfunction on Windows. This is one area where text=auto is not sufficient — you need explicit eol directives.

Recommended Configuration

# Unix scripts (must be LF)
*.sh     text eol=lf
*.bash   text eol=lf
*.zsh    text eol=lf
*.fish   text eol=lf
*.csh    text eol=lf
*.ksh    text eol=lf

# Makefiles (must be LF)
Makefile  text eol=lf
makefile  text eol=lf
*.mk      text eol=lf
GNUmakefile text eol=lf

# Docker (must be LF)
Dockerfile    text eol=lf
Dockerfile.*  text eol=lf
*.dockerfile  text eol=lf
docker-compose.yml text eol=lf

# CI configuration (must be LF)
.travis.yml     text eol=lf
.gitlab-ci.yml  text eol=lf
Jenkinsfile     text eol=lf

# Windows scripts (must be CRLF)
*.bat    text eol=crlf
*.cmd    text eol=crlf
*.ps1    text eol=crlf
*.psm1   text eol=crlf
*.psd1   text eol=crlf

# Git hooks (must be LF)
.husky/* text eol=lf

The Shebang Problem

When a Unix system tries to execute a script with CRLF endings, the shebang line (#!/bin/bash) is interpreted as #!/bin/bash\r. The kernel looks for an interpreter called /bin/bash\r (with a carriage return), which doesn't exist:

/bin/bash^M: bad interpreter: No such file or directory

This error is cryptic and hard to debug, especially in CI/CD pipelines where the developer doesn't have direct terminal access.

Docker and CRLF

Docker builds on Linux will fail if shell commands in the Dockerfile or entrypoint scripts have CRLF endings. A common symptom:

standard_init_linux.go: exec user process caused "no such file or directory"

Git Hooks

Git hooks (.husky/*, .git/hooks/*) are shell scripts executed by Git itself. They must have LF endings and executable permissions. The .gitattributes handles the line endings; chmod +x handles permissions.

Testing Line Endings

Verify your line endings are correct:

# Check for CRLF in a file
file script.sh
# Output: "script.sh: Bourne-Again shell script, ASCII text executable"
# vs: "script.sh: Bourne-Again shell script, ASCII text executable, with CRLF line terminators"