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⇤ ← Revision 1 as of 2007-05-02 22:55:48
Size: 620
Comment:
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Size: 618
Comment: small clean-up
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| Deletions are marked like this. | Additions are marked like this. |
| Line 3: | Line 3: |
| The dirty (but not quick) way would be {{{sed -n ${n}p "$file"}}} but this reads the whole input file, even if you only wanted the third line. | The dirty (but not quick) way would be: {{{ sed -n ${n}p "$file" }}} |
| Line 5: | Line 8: |
| The following {{{sed}}} command line reads a file printing nothing (-n). At line $n the command "p" is run, printing it, with a "q" afterwards: quit the program. | but this reads the whole input file, even if you only wanted the third line. |
| Line 7: | Line 10: |
| This one avoids that problem: | |
| Line 11: | Line 15: |
| Another way, more obvious to some, is to grab the last line from a listing of the first n lines: | At line $n the command "p" is run, printing it, with a "q" afterwards: quit the program. Another way, more obvious to some, is to grab the last line from a listing of the first ''n'' lines: |
| Line 16: | Line 22: |
| Using awk: | Another approach, using ["AWK"]: |
| Line 18: | Line 24: |
| awk 'NR==n{print;exit}' file | awk "NR==$n{print;exit}" file |
How can I print the n'th line of a file?
The dirty (but not quick) way would be:
sed -n ${n}p "$file"but this reads the whole input file, even if you only wanted the third line.
This one avoids that problem:
sed -n "$n{p;q;}" "$file"At line $n the command "p" is run, printing it, with a "q" afterwards: quit the program.
Another way, more obvious to some, is to grab the last line from a listing of the first n lines:
head -n $n $file | tail -n 1
Another approach, using ["AWK"]:
awk "NR==$n{print;exit}" file