GAWK: Effective AWK Programming

More documents

Recommendations

Info

312 GAWK: Effective AWK ProgrammingLogical ExpressionAn expression using the operators for logic, AND, OR, and NOT, written ‘&&’,‘||’, and ‘!’ in awk. Often called Boolean expressions, after the mathematicianwho pioneered this kind of mathematical logic.LvalueMatchingAn expression that can appear on the left side of an assignment operator. Inmost languages, lvalues can be variables or array elements. In awk, a fielddesignator can also be used as an lvalue.The act of testing a string against a regular expression. If the regexp describesthe contents of the string, it is said to match it.MetacharactersCharacters used within a regexp that do not stand for themselves. Instead,they denote regular expression operations, such as repetition, grouping, or alternation.Null StringA string with no characters in it. It is represented explicitly in awk programsby placing two double quote characters next to each other (""). It can appearin input data by having two successive occurrences of the field separator appearnext to each other.Number A numeric-valued data object. Modern awk implementations use doubleprecisionfloating-point to represent numbers. Very old awk implementationsuse single-precision floating-point.OctalBase-eight notation, where the digits are 0–7. Octal numbers are written in Cusing a leading ‘0’, to indicate their base. Thus, 013 is 11 (one times 8 plus 3).P1003.2 See “POSIX.”PatternPOSIXPrecedencePrivatePatterns tell awk which input records are interesting to which rules.A pattern is an arbitrary conditional expression against which input is tested.If the condition is satisfied, the pattern is said to match the input record. Atypical pattern might compare the input record against a regular expression.(See Section 6.1 [Pattern Elements], page 96.)The name for a series of standards that specify a Portable Operating Systeminterface. The “IX” denotes the Unix heritage of these standards. The mainstandard of interest for awk users is IEEE Standard for Information Technology,Standard 1003.2-1992, Portable Operating System Interface (POSIX) Part 2:Shell and Utilities. Informally, this standard is often referred to as simply“P1003.2.”The order in which operations are performed when operators are used withoutexplicit parentheses.Variables and/or functions that are meant for use exclusively by library functionsand not for the main awk program. Special care must be taken whennaming such variables and functions. (See Section 12.1 [Naming Library FunctionGlobal Variables], page 186.)
Glossary 313Range (of input lines)A sequence of consecutive lines from the input file(s). A pattern can specifyranges of input lines for awk to process or it can specify single lines. (SeeSection 6.1 [Pattern Elements], page 96.)RecursionWhen a function calls itself, either directly or indirectly. If this isn’t clear, referto the entry for “recursion.”RedirectionRedirection means performing input from something other than the standardinput stream, or performing output to something other than the standard outputstream.You can redirect the output of the print and printf statements to a file or asystem command, using the ‘>’, ‘>>’, ‘|’, and ‘|&’ operators. You can redirectinput to the getline statement using the ‘
Page 1 and 2:
GAWK: Effective AWK ProgrammingA Us
Page 3:
To Miriam, for making me complete.T
Page 6 and 7:
iiGAWK: Effective AWK ProgrammingTa
Page 8 and 9:
ivGAWK: Effective AWK Programming5
Page 10 and 11:
viGAWK: Effective AWK Programming10
Page 12 and 13:
viiiGAWK: Effective AWK Programming
Page 14 and 15:
2 GAWK: Effective AWK Programmingea
Page 16 and 17:
4 GAWK: Effective AWK ProgrammingAf
Page 18 and 19:
6 GAWK: Effective AWK ProgrammingCh
Page 20 and 21:
8 GAWK: Effective AWK ProgrammingGN
Page 22 and 23:
10 GAWK: Effective AWK Programmingt
Page 24 and 25:
12 GAWK: Effective AWK ProgrammingT
Page 26 and 27:
14 GAWK: Effective AWK Programmingp
Page 28 and 29:
16 GAWK: Effective AWK Programming$
Page 30 and 31:
Page 32 and 33:
20 GAWK: Effective AWK Programming
Page 34 and 35:
22 GAWK: Effective AWK ProgrammingH
Page 36 and 37:
24 GAWK: Effective AWK Programming2
Page 38 and 39:
26 GAWK: Effective AWK Programming\
Page 40 and 41:
28 GAWK: Effective AWK Programming[
Page 42 and 43:
30 GAWK: Effective AWK Programmings
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
40 GAWK: Effective AWK Programming$
Page 54 and 55:
42 GAWK: Effective AWK Programmingh
Page 56 and 57:
Page 58 and 59:
46 GAWK: Effective AWK ProgrammingB
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
54 GAWK: Effective AWK Programming{
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
62 GAWK: Effective AWK Programming%
Page 76 and 77:
Page 78 and 79:
66 GAWK: Effective AWK ProgrammingI
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
72 GAWK: Effective AWK ProgrammingS
Page 86 and 87:
74 GAWK: Effective AWK Programmingo
Page 88 and 89:
Page 90 and 91:
78 GAWK: Effective AWK Programmingh
Page 92 and 93:
80 GAWK: Effective AWK Programmingf
Page 94 and 95:
82 GAWK: Effective AWK Programmingx
Page 96 and 97:
Page 98 and 99:
86 GAWK: Effective AWK ProgrammingA
Page 100 and 101:
88 GAWK: Effective AWK ProgrammingU
Page 102 and 103:
90 GAWK: Effective AWK ProgrammingI
Page 104 and 105:
92 GAWK: Effective AWK ProgrammingS
Page 106 and 107:
94 GAWK: Effective AWK ProgrammingA
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275: 262 GAWK: Effective AWK Programming
Page 364: 352 GAWK: Effective AWK Programming
show all

GAWK: Effective AWK Programming

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?