diff options
Diffstat (limited to 'bash.html.markdown')
| -rw-r--r-- | bash.html.markdown | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/bash.html.markdown b/bash.html.markdown index 211d2944..f3c9cccc 100644 --- a/bash.html.markdown +++ b/bash.html.markdown @@ -83,7 +83,7 @@ echo Hello, $Name! # We have the usual if structure: # use 'man test' for more info about conditionals -if [ $Name -ne $USER ] +if [ $Name != $USER ] then echo "Your name isn't your username" else @@ -91,12 +91,12 @@ else fi # NOTE: if $Name is empty, bash sees the above condition as: -if [ -ne $USER ] +if [ != $USER ] # which is invalid syntax # so the "safe" way to use potentially empty variables in bash is: -if [ "$Name" -ne $USER ] ... +if [ "$Name" != $USER ] ... # which, when $Name is empty, is seen by bash as: -if [ "" -ne $USER ] ... +if [ "" != $USER ] ... # which works as expected # There is also conditional execution @@ -130,6 +130,15 @@ ls -l # Lists every file and directory on a separate line # .txt files in the current directory: ls -l | grep "\.txt" +# Since bash works in the context of a current directory, you might want to +# run your command in some other directory. We have cd for changing location: +cd ~ # change to home directory +cd .. # go up one directory + # (^^say, from /home/username/Downloads to /home/username) +cd /home/username/Documents # change to specified directory +cd ~/Documents/.. # still in home directory..isn't it?? + + # You can redirect command input and output (stdin, stdout, and stderr). # Read from stdin until ^EOF$ and overwrite hello.py with the lines # between "EOF": |