How to use OR condition inside tcsh if statement
There is some confusions:
- Your first script is written in bourne-shell
- Your script did not mention what is the shell should be used to interpret it (that may lead to some confusion depending on the way you execute it)
- You second script is a tcsh script but with misleading syntax
- It looks like you don't know what
Modify the first script like this:
#!/bin/sh if [ "$1" == "hi" -o "$2" == "hello" ]; then echo hi else echo hello fi
This means that if executable this script will use
/bin/sh to interpret it. But, if you force the shell with commands:
% sh -x test hi hi + '[' hi == hi -o hi == hello ']' + echo hi hi % tcsh -x test hi hi if [ hi = hi -o hi = hello ] if: Expression Syntax. then then: Command not found. %
you can observe that using the wrong shell leads to some syntax errors.
If you want to write a tcsh script, this is a solution:
#!/bin/tcsh if ( "$1" == "hi" || "$2" == "hello" ) then echo hi else echo hello endif
if is different because tcsh has internal testing features, which standard bourne shell doesn't have. In bourne shell testing is made using the external command
test which has an alias
[. So you may read the documentation about
testsyntax in the manual:
SYNOPSIS test expression [ expression ] ... s1 = s2 True if the strings s1 and s2 are identical. ... expression1 -o expression2 True if either expression1 or expression2 are true.
if, read the manual for tcsh (or csh its parent):
if (expr) command If expr (an expression, as described under Expressions) evalu- ates true, then command is executed. Variable substitution on command happens early, at the same time it does for the rest of the if command. command must be a simple command, not an alias, a pipeline, a command list or a parenthesized command list, but it may have arguments. Input/output redirection occurs even if expr is false and command is thus not executed; this is a bug. if (expr) then ... else if (expr2) then ... else ... endif If the specified expr is true then the commands to the first else are executed; otherwise if expr2 is true then the commands to the second else are executed, etc. Any number of else-if pairs are possible; only one endif is needed. The else part is likewise optional. (The words else and endif must appear at the beginning of input lines; the if must appear alone on its input line or after an else.) Logical, arithmetical and comparison operators These operators are similar to those of C and have the same precedence. They include || && | ^ & == != =~ !~ <= >= < > << >> + - * / % ! ~ ( ) ...
Related videos on Youtube
monk 8 months
I am trying to use an OR condition inside an IF statement in tcsh shell. Same statement works in CSH.
Example statement: (cat tesh.sh)
if [ "$1" == "hi" -o "$2" == "hello" ];then echo hi else echo hello fi
Now if I execute this sample script I get the following errors:
 % sh -x test hi hi hello + test hi hi hello test: hi: A test command parameter is not valid. + exit 1  % sh -x test hi hi + test hi hi test: test: Specify a parameter with this command. + exit 1  % sh -x test hi hello + test hi hello test: test: Specify a parameter with this command. + exit 1  % sh -x test hi hello + test hi hello test: test: Specify a parameter with this command. + exit 1  %
Please suggest what can be done?
 % uname -s HP-UX  %  % echo $SHELL /bin/tcsh  %
cat new_test.txt if ([ $1 == 1 ] || [ $2 == 1 ]) then echo $1 and $2 fi ./new_test.txt 1 1 ./new_test.txt: ==: A test command parameter is not valid. ./new_test.txt: ==: A test command parameter is not valid.
cat suggested.sh if (($1 == 1) || ($2 == 1)) ; then echo "$1 and $2" ; fi ./suggested.sh 1 1 ./suggested.sh: 1: not found. ./suggested.sh: 1: not found.