1 ALIAS(1) User Commands ALIAS(1) 2 3 4 5 NAME 6 alias, unalias - create or remove a pseudonym or shorthand for a 7 command or series of commands 8 9 SYNOPSIS 10 /usr/bin/alias [alias-name[= string...]] 11 12 13 /usr/bin/unalias alias-name... 14 15 16 /usr/bin/unalias -a 17 18 19 csh 20 alias [name [def]] 21 22 23 unalias pattern 24 25 26 ksh93 27 alias [-ptx] [name[= value]...] 28 29 30 unalias [-a] [name...] 31 32 33 DESCRIPTION 34 The alias and unalias utilities create or remove a pseudonym or 35 shorthand term for a command or series of commands, with different 36 functionality in the C-shell and Korn shell environments. 37 38 /usr/bin/alias 39 The alias utility creates or redefines alias definitions or writes the 40 values of existing alias definitions to standard output. An alias 41 definition provides a string value that replaces a command name when it 42 is encountered. 43 44 45 An alias definition affects the current shell execution environment and 46 the execution environments of the subshells of the current shell. When 47 used as specified by this document, the alias definition does not 48 affect the parent process of the current shell nor any utility 49 environment invoked by the shell. 50 51 /usr/bin/unalias 52 The unalias utility removes the definition for each alias name 53 specified. The aliases are removed from the current shell execution 54 environment. The -a option removes all alias definitions from the 55 current execution environment. 56 57 csh 58 alias assigns def to the alias name. The assigned def is a list of 59 words that can contain escaped history-substitution metasyntax. name 60 is not allowed to be alias or unalias. If def is omitted, the alias 61 name is displayed along with its current definition. If both name and 62 def are omitted, all aliases are displayed. 63 64 65 Because of implementation restrictions, an alias definition must have 66 been entered on a previous command line before it can be used. 67 68 69 unalias discards aliases that match (filename substitution) pattern. 70 All aliases can be removed by `unalias *'. 71 72 ksh93 73 alias creates or redefines alias definitions or writes the existing 74 alias definitions to standard output. 75 76 77 An alias definition provides a string value that replaces a command 78 name when the command is read. Alias names can contain any printable 79 character that is not special to the shell. If an alias value ends in a 80 SPACE or TAB, the word following the command name the alias replaces is 81 also checked to see whether it is an alias. 82 83 84 If no names are specified, the names and values of all aliases are 85 written to standard output. Otherwise, for each name that is specified, 86 and =value is not specified, the current value of the alias 87 corresponding to name is written to standard output. If =value is 88 specified, the alias name is created or redefined. 89 90 91 alias is built-in to the shell as a declaration command so that field 92 splitting and pathname expansion are not performed on the arguments. 93 Tilde expansion occurs on value. An alias definition only affects 94 scripts read by the current shell environment. It does not affect 95 scripts run by this shell. 96 97 98 unalias removes the definition of each named alias from the current 99 shell execution environment, or all aliases if -a is specified. It does 100 not affect any commands that have already been read and subsequently 101 executed. 102 103 OPTIONS 104 The following option is supported by unalias: 105 106 -a 107 Removes all alias definitions from the current shell execution 108 environment. 109 110 111 ksh93 112 The following options are supported by alias: 113 114 -p 115 Causes the output to be in the form of alias commands that can be 116 used as input to the shell to recreate the current aliases. 117 118 119 -t 120 Specifies tracked aliases. 121 122 Tracked aliases connect a command name to the command's pathname, 123 and are reset when the PATH variable is unset. The tracked 124 aliases feature is now obsolete. 125 126 127 -x 128 Ignored, this option is obsolete. 129 130 131 132 The following option is supported by unalias: 133 134 -a 135 Causes all alias definitions to be removed. name operands are 136 optional and ignored if specified. 137 138 139 OPERANDS 140 The following operands are supported: 141 142 alias 143 alias-name 144 Write the alias definition to standard output. 145 146 147 unalias 148 alias-name 149 The name of an alias to be removed. 150 151 152 alias-name=string 153 Assign the value of string to the alias alias- 154 name. 155 156 157 158 If no operands are specified, all alias definitions are written to 159 standard output. 160 161 OUTPUT 162 The format for displaying aliases (when no operands or only name 163 operands are specified) is: 164 165 "%s=%s\n" name, value 166 167 168 169 170 The value string is written with appropriate quoting so that it is 171 suitable for reinput to the shell. 172 173 EXAMPLES 174 Example 1 Modifying a Command's Output 175 176 177 This example specifies that the output of the ls utility is columnated 178 and more annotated: 179 180 181 example% alias ls="ls -CF" 182 183 184 185 Example 2 Repeating Previous Entries in the Command History File 186 187 188 This example creates a simple "redo" command to repeat previous entries 189 in the command history file: 190 191 192 example% alias r='fc -s' 193 194 195 196 Example 3 Specifying a Command's Output Options 197 198 199 This example provides that the du utility summarize disk output in 200 units of 1024 bytes: 201 202 203 example% alias du=du -k 204 205 206 207 Example 4 Dealing with an Argument That is an Alias Name 208 209 210 This example sets up the nohup utility so that it can deal with an 211 argument that is an alias name: 212 213 214 example% alias nohup="nohup " 215 216 217 218 ENVIRONMENT VARIABLES 219 See environ(5) for descriptions of the following environment variables 220 that affect the execution of alias and unalias: LANG, LC_ALL, LC_CTYPE, 221 LC_MESSAGES, and NLSPATH. 222 223 EXIT STATUS 224 The following exit values are returned: 225 226 0 227 Successful completion. 228 229 230 alias 231 >0 232 One of the alias-name operands specified did not have an alias 233 definition, or an error occurred. 234 235 236 unalias 237 >0 238 One of the alias-name operands specified did not represent a 239 valid alias definition, or an error occurred. 240 241 242 ATTRIBUTES 243 See attributes(5) for descriptions of the following attributes: 244 245 csh, ksh 246 247 +--------------------+-------------------+ 248 | ATTRIBUTE TYPE | ATTRIBUTE VALUE | 249 +--------------------+-------------------+ 250 |Interface Stability | Committed | 251 +--------------------+-------------------+ 252 |Standard | See standards(5). | 253 +--------------------+-------------------+ 254 255 ksh93 256 257 +--------------------+-----------------+ 258 | ATTRIBUTE TYPE | ATTRIBUTE VALUE | 259 +--------------------+-----------------+ 260 |Interface Stability | Uncommitted | 261 +--------------------+-----------------+ 262 263 SEE ALSO 264 csh(1), ksh(1), ksh93(1), shell_builtins(1), attributes(5), environ(5), 265 standards(5) 266 267 268 269 February 9, 2021 ALIAS(1)