cat <filename>
logs a file
head -n <number> <filename>
logs the first number lines of a file
tail -n <number> <filename>
logs the last number lines of a file
grep <text> <filename>
logs the lines containing text on the file
-v --invert-match
logs the lines not containing text on the file-i --ignore-case
matches independently of the case-E
support for all regex instead of <text>
-r
recursively searchs in all files. Use it with a directory instead of filenamefind <directory-to-look> -name <name>
finds a file or directory with name. Use -iname
for case insensitive search. Add -type d
to look just for directories.
tree
logs the directory structure like a tree, including nested
sed 's/<oldExpresion>/<newExpresion>/' <filename>
logs the file substituting oldExpresion for newExpresion
-E
support for all regex instead of <oldExpresion>
-i 'subfix'
modify the original file and save the original one adding subfix
to the name (for example, .old). If no subfix is provided, will not create the backupmv <filename1> <filename2>
renames filename1 to filename2
> <filename>
Will write the shell stdout to the file (replacing content)
2> <filename>
Will write the shell stderror to the file (replacing content)
&> <filename>
Will write the shell stdout and stderror to the file (replacing content)
>> <filename>
Will append the shell stdout to the file
echo $?
Will print the exit code of the last command. 0 means no error.
To hide the output of a command, use &> /dev/null
<command> | <command>
Will run the first command and pass its output as the argument for the second command<command> ; <command>
Will run both commands, independently of their output (i/ errors)