Daily Archives: 20120504

xargs

Maybe, I’m the lost person to realize the functional awesomeness of xargs(1).

Without xargs(1):

% i=0; for j in $(jot 100 1); do if [ $i = 4 ]; then printf "%2x %2x %2x %2x %2x\n" $s $j; s=""; i=0; else i=$((i+1)); s="$s $j"; fi; done
 1  2  3  4  5
 6  7  8  9  a
 b  c  d  e  f
10 11 12 13 14
15 16 17 18 19
1a 1b 1c 1d 1e
1f 20 21 22 23
24 25 26 27 28
29 2a 2b 2c 2d
2e 2f 30 31 32
33 34 35 36 37
38 39 3a 3b 3c
3d 3e 3f 40 41
42 43 44 45 46
47 48 49 4a 4b
4c 4d 4e 4f 50
51 52 53 54 55
56 57 58 59 5a
5b 5c 5d 5e 5f
60 61 62 63 64

With xargs(1):

% jot 100 1 |xargs -n 5 printf "%2x %2x %2x %2x %2x\n"
 1  2  3  4  5
 6  7  8  9  a
 b  c  d  e  f
10 11 12 13 14
15 16 17 18 19
1a 1b 1c 1d 1e
1f 20 21 22 23
24 25 26 27 28
29 2a 2b 2c 2d
2e 2f 30 31 32
33 34 35 36 37
38 39 3a 3b 3c
3d 3e 3f 40 41
42 43 44 45 46
47 48 49 4a 4b
4c 4d 4e 4f 50
51 52 53 54 55
56 57 58 59 5a
5b 5c 5d 5e 5f
60 61 62 63 64