Comments on: Bash shell script to convert string from lower to upper case and vice versa

By: Sara Mithal

Sara Mithal — Sat, 18 Dec 2010 06:05:00 +0000

The following command helps in converting all contents of a file from lower case to upper case.

bash# tr ‘[:lower:]‘ ‘[:upper:]‘ output.txt

bash# tr ‘[:upper:]‘ ‘[:lower:]‘ output.txt

By: Sara Mithal

Sara Mithal — Sat, 18 Dec 2010 06:02:23 +0000

The same can be represented in this way as well.

Lower case to Upper case:

bash# toUpper() { echo $1 | tr “[a-z]” “[A-Z]”; }
bash# toUpper myname
MYNAME
bash#

Upper case to Lower case:

bash# toLower() { echo $1 | tr “[A-Z]” “[a-z]”; }
bash# toLower MYNAME
myname
bash#

By: Neo

Neo — Sat, 01 Aug 2009 12:00:34 +0000

Nope. The example given in the article assumes the function to be placed in a bash script. But you are trying to fit all three lines in a single line. So you need a semi-colon.

See the following example:

[neo@techpulp ~]# toUpper() { echo $1 | tr “[:lower:]” “[:upper:]” }
> bash: syntax error: unexpected end of file
[neo@techpulp ~]# toUpper() { echo $1 | tr “[:lower:]” “[:upper:]”; }
[neo@techpulp ~]#

You can see in the first command where a semi-colon is not given, the bash is still expecting some input so I had to press Ctrl+D to get out.

But in the second command where a semi-colon is given, bash is expecting no more input.

By: Dmitri Arkhipov

Dmitri Arkhipov — Thu, 30 Jul 2009 23:30:39 +0000

Maybe it’s because I’m using cygwin, but I had to do:
toUpper() { echo $1 | tr “[:lower:]” “[:upper:]” ; }

Note the semicolon…