Commands cat chmod cp mv ls –l ls ls -a date export find grep mkdir rmdir more less rm sort sleep wc -L kill kill -L diff cd sort whence umask umask -s who bg fg ln ln -s tail tail -f head what who am I history exec nice arch chown mount umount Arithmetic
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- Arithmetic expressions
- Shell variables used by ksh
- Conditional Expression Primitives
- Quoting
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Commands cat
chmod cp mv ls –l ls ls -a date export
find grep
mkdir rmdir
more less
rm sort
sleep wc -l
kill kill -l
diff cd sort whence umask
umask -S who
bg fg ln ln -s tail
tail -f head
what who am i
history exec
nice arch
chown mount
umount Arithmetic expressions <= - less than or equal to >= - greater than or equal to < - less than > - greater than == - equal to * - multiplication / - division + - addition - - subtraction Shell variables used by ksh PATH - Path search directories SHELL - Pathname of the Shell TERM - Terminal type HOME - Your home directory Shell variables set by ksh PWD - Working directory LINENO - Current line number PPID - Parent process id Shell statements printf “string” - output a string of information echo $COUNTER - output content of the variable COUNTER echo “Text line” - output text line to monitor from script printf $NUMBER - output content of the variable NUMBER NUMBER=$(($NUMBER-1)) - decrease NUMBER value by one $# - number of positional parameters $? - return value $$ - process id of this shell $! - background process id $1 - first command line argument $2 - second command line argument Conditional Expression Primitives -r - true if file exists and is readable -w - true if file exists and is writable -x - true if file exists and is executable -f - true if file exists and is a file -d - true if file exists and is a directory -eq - true if value of exp1 and exp2 are equal -ne - true if value of exp1 and exp2 are not equal -gt - true if value of exp1 is greater than value of exp2 -ge - true if value of exp1 is greater than or equal to value of exp2 -lt - true if value of exp1 is less than value of exp2 -le - true if value of exp1 less than or equal to value of exp2 Quoting “…” - double quotes (interpolation) `…` - single back ticks (command execution) I/O Operators < Variable - read from file (cat < test_file) > Variable - write to a file (cat > test_file) Variable >> Variable - append content of file_1 to the end of file_2 (cat file_1 >> file_2) & - Execute process in background Syntax while [ … ] do …
if [ … ] then
… fi
then …
… fi
test x+1 –gt y
| AWK Table 5 | | Escape Sequences | |Sequence Description | +-------------------------------------------------------+ |\a ASCII bell (NAWK only) | |\b Backspace | |\f Formfeed | |\n Newline | |\r Carriage Return | |\t Horizontal tab | |\v Vertical tab (NAWK only) | |\ddd Character (1 to 3 octal digits) (NAWK only) | |\xdd Character (hexadecimal) (NAWK only) | | Any character c | +-------------------------------------------------------+ Let us create employee.txt file which has the following content, which will be used in the examples mentioned below. $cat employee.txt 100 Thomas Manager Sales $5,000 200 Jason Developer Technology $5,500 300 Sanjay Sysadmin Technology $7,000 400 Nisha Manager Marketing $9,500 500 Randy DBA Technology $6,000 Awk has number of built in variables. For each record i.e line, it splits the record delimited by whitespace character by default and stores it in the $n variables. If the line has 4 words, it will be stored in $1, $2, $3 and $4. $0 represents whole line. NF is a built in variable which represents total number of fields in a record. $ awk '{print $2,$5;}' employee.txt Thomas $5,000 Jason $5,500 Sanjay $7,000 Nisha $9,500 Randy $6,000
Thomas $5,000 Jason $5,500 Sanjay $7,000 Nisha $9,500 Randy $6,000 In the above example $2 and $5 represents Name and Salary respectively. We can get the Salary using $NF also, where $NF represents last field. In the print statement ‘,’ is a concatenator. Download 12.64 Kb. Share with your friends:
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