问题
I am trying to collect information on the amount of space left on different servers. So when I execute df -k i get output as:
Filesystem 1024-blocks Used Avail Capacity Mounted on
/dev/ad1s1f 125925198 2568970 113282214 2% /builds
And sometimes the output comes as :
Filesystem 1K-blocks Used Available Use% Mounted on
10.102.1.123:/storage/disk1/build
10735331328 10597534720 137796608 99% /buildbackup
Now I want to fetch data on the disk space available. So let me know how to fetch data from a particular column.
回答1:
You can for example say:
df --output=source,avail
Or as commented by Tim Bunce, you can use --direct to prevent the long filesystem name make the line split in two. This will show the filesystem as -.
From man df:
--output[=FIELD_LIST]
use the output format defined by FIELD_LIST, or print all fields if FIELD_LIST is omitted.
...
FIELD_LIST is a comma-separated list of columns to be included. Valid field names are: 'source', 'fstype', 'itotal', 'iused', 'iavail', 'ipcent', 'size', 'used', 'avail', 'pcent' and 'target' (see info page).
--direct
show statistics for a file instead of mount point
Test
$ df --output=source,avail
Filesystem Avail
/dev/sda7 321675536
回答2:
fedorqui's solution is cleaner, but only works for df
A more general approach is to collapse multiple spaces to a single space using sed 's/ \+/ /g' or tr -s ' ', then use cut with spaces as delimiters: cut -d" " -f 4
So the command is:
df -k | tr -s ' ' | cut -d" " -f 4
Which results in something like this:
Available
26027952
854220
68376208
The same approach will work with other commands that output data to columns.
For instance ls -l | tr -s ' ' | cut -d" " -f 6,7,8
will print the time columns from ls -l:
Dec 30 17:46
Mar 1 15:33
Mar 1 14:58
Mar 2 00:00
Jan 5 14:20
Mar 1 15:33
Feb 26 11:57
Feb 4 11:11
Mar 1 14:57
来源：https://stackoverflow.com/questions/28809148/how-to-select-a-particular-column-in-linux-df-command