Bash – Pass command line parameters to a program inside the shell script

$> cat ./deploymLog.sh 
#!/bin/bash

name=$1
log_file="Logone.txt"

if [[ -n "$name" ]]; then
    echo "$1=$( date +%s )" >> ${log_file}
else
    echo "argument error"
fi

The first argument from a command line can be found with the positional parameter $1. [[ -n "$name" ]] tests to see if $name is not empty. date +%s returns the current timestamp in Unix time. The >> operator is used to write to a file by appending to the existing data in the file.

$> ./deploymLog.sh tt

$> cat Logone.txt 
tt=1329810941

$> ./deploymLog.sh rr

$> cat Logone.txt 
tt=1329810941
rr=1329810953

For more readable timestamp you could play with date arguments.

$@ expands to separate words (whereas $* expands to a single word), as explained in the bash manual. Thus, when you write

zenity --text="$@"

it expands to

zenity --text="$1" "$2" "$3"

However, shell variable assignments do not undergo word splitting. Note that field / word splitting is omitted in the list of expansions for variable assignments in the bash manual. This behavior is consistent with the POSIX spec. So, when you write

text="$@"

the variable text gets all of the positional parameters as a single word, equivalent to if you had written text="$*". Indeed, this is the reason double quotes are often unnecessary in variable assignments. Both

text=$@

and

text=$*

are perfectly safe.

So,

text=$@
zenity --option="$text"

expands "$text" to a single word, which is why this works. Note that the --option="$@" is just a normal argument to the command zenity, and not a shell variable assignment, which is why word splitting takes place here but not in text=$@.