Mastering UNIX® Shell Scripting: Bash, Bourne, and Korn Shell Scripting for Programmers, System Administrators, and UNIX Gurus, Second Edition

Index

SYMBOLS

() (parentheses)

command, 15

double-parentheses mathematical test, 117, 337, 338, 346, 363, 414, 575, 609, 682, 734

& (ampersand)

|& (piping to background), 36, 351, 364

&& (logical AND) operator, 13, 20, 570, 813

background execution, 13

bitwise AND operator, 20

escaped, 3, 4

* (asterisk)

multiplication operator, 20

wildcard, 31, 830

^(caret)

^$ (remove blank lines), 669

^# (remove commented out lines), 669, 858

bitwise exclusive OR operator, 20

escaped, 3, 4

start of line, 170, 669, 733, 858, 863

: (colon)

as field delimiter, 157, 159, 167, 536, 537, 569

getops command and, 33, 34, 349, 450, 496

NFS check and, 569, 570

no-op and, 74, 96, 195, 348, 380, 416

$ (dollar sign)

$? (check return code), 29–30, 183–184, 217

$$ (current PID), RANDOM shell variable and, 269, 311, 371, 379, 389

^$ (remove blank line), 669

“$*” (special parameter), 17

“$@” (special parameter), 17

$* (special parameter), 17–18

$@ (special parameter), 17

$ (()) command, 15

elapsed time and, 148

$! operator, 44, 144, 145, 147, 546, 547

blank line, 669

command substitution, 19, 80, 88, 97, 127, 128, 331, 484. See also command substitution

end of line, 170, 863

escaped, 3, 4, 404, 664

variable name and, 15, 28, 304

. (dots)

escaped, 3, 4

series of, 43, 143–145, 967

“ (double quotes)

around variables, 18, 50, 160, 169, 247, 516, 517, 570

command substitution and, 18, 50

command-line switches in, 450

disable command arguments with, 797

escaped, 3, 4

special parameters with, 17

usage for, 18

= (equal ...