Introduction........................................................ iv Section 1: Revisions to General..................................... 1 1.1 Scope...................................................... 1 Section 2: Revisions to Terminology and General Requirements........ 7 2.2.1 Terminology....................................... 7 2.2.2 General Terms..................................... 8 2.3 Built-in Utilities......................................... 11 2.6 Environment Variables...................................... 12 2.13.2 Symbolic Constants for Portability Specifications.................................... 14 2.14 Terminal Characteristics................................... 16 Section 3: Revisions to Shell Command Language...................... 19 3.1 Shell Definitions.......................................... 19 3.3.1 Alias Substitution................................ 19 3.5.3 Variables......................................... 21 3.12 Shell Execution Environment................................ 24 3.14.11 set - Set/unset options and positional parameters........................................ 25 Section 4: Revisions to Execution Environment Utilities............. 29 4.12 command - Execute a simple command......................... 29 4.32 kill - Terminate or signal processes....................... 32 4.40 mailx - Process messages................................... 33 4.52 read - Read a line from standard input..................... 64 4.56 sh - Shell, the standard command language interpreter...... 65 4.70 wait - Await Process Completion............................ 80 Section 5: User Portability Utilities Option........................ 83 5.1 alias - Define or display aliases.......................... 85 5.2 at - Execute commands at a later time...................... 89 5.3 batch - Execute commands when the system load permits...... 101 5.4 bg - Run jobs in the background............................ 104 5.5 crontab - Schedule periodic background work................ 108 5.6 csplit - Split files based on context...................... 113 5.7 ctags - Create a tags file................................. 118 5.8 df - Report free disk space................................ 124 5.9 du - Estimate file space usage............................. 129 5.10 ex - Text editor........................................... 133 5.11 expand - Convert tabs to spaces............................ 175 5.12 fc - Process command history list.......................... 178 5.13 fg - Run jobs in the foreground............................ 186 5.14 file - Determine file type................................. 189 5.15 jobs - Display status of jobs in the current session....... 195 5.16 man - Display system documentation......................... 200 5.17 mesg - Permit or deny messages............................. 205 5.18 more - Display files on a page-by-page basis............... 208 5.19 newgrp - Change to a new group............................. 223 5.20 nice - Invoke a utility with an altered system scheduling priority................................................... 227 5.21 nm - Write the name list of an object file................. 233 5.22 patch - Apply changes to files............................. 238 5.23 ps - Report process status................................. 246 5.24 renice - Set system scheduling priorities of running processes.................................................. 255 5.25 split - Split files into pieces............................ 260 5.26 strings - Find printable strings in files.................. 265 5.27 tabs - Set terminal tabs................................... 269 5.28 talk - Talk to another user................................ 273 5.29 time - Time a simple command............................... 278 5.30 tput - Change terminal characteristics..................... 283 5.31 unalias - Remove alias definitions......................... 287 5.32 unexpand - Convert spaces to tabs.......................... 290 5.33 uudecode - Decode a binary file............................ 294 5.34 uuencode - Encode a binary file............................ 297 5.35 vi - Screen-oriented (visual) display editor............... 301 5.36 who - Display who is on the system......................... 342 5.37 write - Write to another user.............................. 346 Annex E (informative) Rationale and Notes........................... 351 E.4 Excluded Utilities......................................... 351 Annex F (informative) Balloting Instructions........................ 355 Identifier Index.................................................... 367 Alphabetic Topical Index............................................ 369 TABLES Table 2-100 - Job Control Job ID Formats.......................... 9 Table 2-101 - Control Character Names............................. 17 Table 5-100 - file Output Strings................................. 191 Table 5-101 - ps Variable Names and Default Headers............... 251