Cas's answer is good, but it assumes sane filenames; in particular it is assumed that filenames will not contain newlines.

There's no good reason to make this assumption here, since it is quite simple (and actually cleaner in my opinion) to handle that case correctly as well:

find . -type f -exec sh -c 'file "$1" | grep -q "ASCII text"' sh {} \; -exec flip -u {} \; 

The find command only makes use of POSIX-specified features. Using -exec to run arbitrary commands as boolean tests is simple, robust (handles odd filenames correctly), and more portable than -print0.

In fact, all parts of the command are specified by POSIX except for flip.

Note that file doesn't guarantee accuracy of the results it returns. However, in practice grepping for "ASCII text" in its output is quite reliable.

(It might miss some text files perhaps, but is very very unlikely to incorrectly identify a binary file as "ASCII text" and mangle it—so we are erring on the side of caution.)

Cas's answer is good, but it assumes sane filenames; in particular it is assumed that filenames will not contain newlines.

There's no good reason to make this assumption here, since it is quite simple (and actually cleaner in my opinion) to handle that case correctly as well:

find . -type f -exec sh -c 'file "$1" | grep -q "ASCII text"' sh {} \; -exec flip -u {} \; 

The find command only makes use of POSIX-specified features. Using -exec to run arbitrary commands as boolean tests is simple, robust (handles odd filenames correctly), and more portable than -print0.

In fact, all parts of the command are specified by POSIX except for flip.

Note that file doesn't guarantee accuracy of the results it returns. However, in practice grepping for "ASCII text" in its output is quite reliable.

(It might miss some text files perhaps, but is very very unlikely to incorrectly identify a binary file as "ASCII text" and mangle it—so we are erring on the side of caution.)

Cas's answer is good, but it assumes sane filenames; in particular it is assumed that filenames will not contain newlines.

There's no good reason to make this assumption here, since it is quite simple (and actually cleaner in my opinion) to handle that case correctly as well:

find . -type f -exec sh -c 'file "$1" | grep -q "ASCII text"' sh {} \; -exec flip -u {} \; 

The find command only makes use of POSIX-specified features. Using -exec to run arbitrary commands as boolean tests is simple, robust (handles odd filenames correctly), and more portable than -print0.

In fact, all parts of the command are specified by POSIX except for flip.

Note that file doesn't guarantee accuracy of the results it returns. However, in practice grepping for "ASCII text" in its output is quite reliable.

Cas's answer is good, but it assumes sane filenames; in particular it is assumed that filenames will not contain newlines.

There's no good reason to make this assumption here, since it is quite simple (and actually cleaner in my opinion) to handle that case correctly as well:

find . -type f -exec sh -c 'file "$1" | grep -q "ASCII text"' sh {} \; -exec flip -u {} \; 

The find command only makes use of POSIX-specified features. Using -exec to run arbitrary commands as boolean tests is simple, robust (handles odd filenames correctly), and more portable than -print0.

In fact, all parts of the command are specified by POSIX except for flip.

Note that file doesn't guarantee accuracy of the results it returns. However, in practice grepping for "ASCII text" in its output is quite reliable.

(It might miss some text files perhaps, but is very very unlikely to incorrectly identify a binary file as "ASCII text" and mangle it—so we are erring on the side of caution.)