8187 |
@item LINENO |
@item LINENO |
8188 |
@evindex LINENO |
@evindex LINENO |
8189 |
Most modern shells provide the current line number in @code{LINENO}. |
Most modern shells provide the current line number in @code{LINENO}. |
8190 |
Its value is the line number of the beginning of the current command |
Its value is the line number of the beginning of the current command. |
8191 |
(see below the output of the here document). The behavior wrt |
Autoconf attempts to execute @command{configure} with a modern shell. |
8192 |
@command{eval} differs according to the shell, but, amusingly, not in |
If no such shell is available, it attempts to implement @code{LINENO} |
8193 |
the case of sub shells: |
with a simple Awk+Sed prepass that replaces the first instance of the |
8194 |
|
string @code{$LINENO} in each line with the line's number. |
8195 |
|
|
8196 |
|
You should not rely on @code{LINENO} within @command{eval}, as the |
8197 |
|
behavior differs in practice. Also, the possibility of the Awk+Sed |
8198 |
|
prepass means that you should not rely on @code{$LINENO} when quoted, |
8199 |
|
when in here-documents, or when in long commands that cross line |
8200 |
|
boundaries or that have multiple instances of $LINENO. Subshells |
8201 |
|
should be OK, though. In the following example, lines 1, 6, and 10 |
8202 |
|
are portable, but the other instances of @code{LINENO} are not: |
8203 |
|
|
8204 |
@example |
@example |
8205 |
@group |
@group |
8211 |
EOF |
EOF |
8212 |
( echo 6. $LINENO ) |
( echo 6. $LINENO ) |
8213 |
eval 'echo 7. $LINENO' |
eval 'echo 7. $LINENO' |
8214 |
|
echo 8. $LINENO $LINENO |
8215 |
|
echo 9. '$LINENO' |
8216 |
|
echo 10. $LINENO ' |
8217 |
|
11.' $LINENO |
8218 |
@end group |
@end group |
8219 |
@group |
@group |
8220 |
$ @kbd{ash lineno} |
$ @kbd{bash-2.05 lineno} |
|
1. |
|
|
3. |
|
|
4. |
|
|
6. |
|
|
7. |
|
|
@end group |
|
|
@group |
|
|
$ @kbd{bash-2.03 lineno} |
|
8221 |
1. 1 |
1. 1 |
8222 |
3. 2 |
3. 2 |
8223 |
4. 2 |
4. 2 |
8224 |
6. 6 |
6. 6 |
8225 |
7. 1 |
7. 1 |
8226 |
|
8. 8 8 |
8227 |
|
9. $LINENO |
8228 |
|
10. 10 |
8229 |
|
11. 10 |
8230 |
@end group |
@end group |
8231 |
@group |
@group |
8232 |
$ @kbd{zsh-3.1.9 lineno} |
$ @kbd{zsh-3.0.6 lineno} |
8233 |
1. 1 |
1. 1 |
8234 |
3. 2 |
3. 2 |
8235 |
4. 2 |
4. 2 |
8236 |
6. 6 |
6. 6 |
8237 |
7. 7 |
7. 7 |
8238 |
|
8. 8 8 |
8239 |
|
9. $LINENO |
8240 |
|
10. 10 |
8241 |
|
11. 10 |
8242 |
@end group |
@end group |
8243 |
@group |
@group |
8244 |
$ @kbd{pdksh-5.2.14 lineno} |
$ @kbd{pdksh-5.2.14 lineno} |
8247 |
4. 2 |
4. 2 |
8248 |
6. 6 |
6. 6 |
8249 |
7. 0 |
7. 0 |
8250 |
|
8. 8 8 |
8251 |
|
9. $LINENO |
8252 |
|
10. 10 |
8253 |
|
11. 10 |
8254 |
|
@end group |
8255 |
|
@group |
8256 |
|
$ @kbd{awk '/\$LINENO/@{printf "%d:", NR@}; @{print@}' lineno |} |
8257 |
|
> @kbd{sed '/\$LINENO/s/^\([^:]*\):\(.*\)\$LINENO/\2\1/' |} |
8258 |
|
> @kbd{sh} |
8259 |
|
1. 1 |
8260 |
|
3. 3 |
8261 |
|
4. 4 |
8262 |
|
6. 6 |
8263 |
|
7. 7 |
8264 |
|
8. 8 |
8265 |
|
9. 9 |
8266 |
|
10. 10 |
8267 |
|
11. 11 |
8268 |
@end group |
@end group |
8269 |
@end example |
@end example |
8270 |
|
|