Bourne Shell Quick Reference Guide:

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Bourne Shell Quick Reference Guide
(Publisher: ASP, Inc.)
Author(s): Anatole Olczak
ISBN: 093573922x
Publication Date: 12/01/91

Program Format:

Patterns in program can be associated with a statement to perform if an input line matches the pattern. The format is:

   pattern { statement }

A missing pattern always matches, and a missing statement prints the current input line.

Patterns:

BEGIN	match before first input line
END	match after last input line
pattern1, pattern2, ..., patternn	match if pattern1, pattern2, or patternn match current input line
pattern1 && pattern2	match if pattern1 and pattern2 match current input line
pattern1 \|\| pattern2	match if pattern1 or pattern2 match current input line
!pattern	match if pattern does not match current input line
/regular-expression/	match if regular-expression matches current input line
relational-expression	match if relational-expression evaluates to true

Flow Control Statements:

break	exit from a for or while loop
continue	execute next for or while loop
delete variable[expression]	delete element expression from array variable
do statement while (expression)	execute statement while expression is true
exit	skip remaining input
for (expression1; expression2; expression3) statement	execute statement while expression2 is true; loop is usually initialized with expression1 and incremented with expression3
for (variable in array) statement	execute statement, setting variable to successive elements in array
if (expression) statement1 [ else statement2 ]	execute statement1 if expression is true, otherwise execute statement2
next	skip rest of the input line
return[expression]	return value of expression
system(command)	execute command and return status
while (expression) statement	execute statement while expression is true

Input/Output Statements:

close(file)	close file
getline	set $0 to next input record; set NF, NR, FNR
getline<file	set $0 to next input from file; set NF
getline var	set var to next input record; set NR, FNR
getline variable<file	set variable to next input record from file
command \| getline	pipe output of command into getline
print	print current input record
print expression	print expression; multiple expressions must be separated with a ","
print expression>file	print expression to file; multiple expressions must be separated with a ","
printf format expression	print expression according to C-like format. Multiple expressions must be separated with a ",". Output can also be appended to file using >> or piped to a command using \|.
printf format expression>file	print expression to file according to C-like format. Multiple expressions must be separated with a ",". Output can also be appended to file using >> or piped to a command using \|.