I want to put a header to file but I get the first comma in the output. Code
#!/bash/bin
ids=(1 10)
filenameTarget=/tmp/result.csv
:> "${filenameTarget}"
echo "masi" > "${filenameTarget}"
header=$(printf ",%s" ${ids[@]}) # http://stackoverflow.com/a/2317171/54964
sed -i "1s/^/${header}\n/" "${filenameTarget}"
Output
,1,10
masi
Expected output
1,10
masi
Debian: 8.5
Bash: 4.30
You left out the
bar=${bar:1}
line from the answer you linked to; you need
header=${header:1}
before your sed line to remove the leading comma.
Instead of using printf, why not use bash's built-in substitutions? From the section on Arrays:
subscripts differ only when the word appears within double quotes. If
the word is double-quoted, ${name[*]} expands to a single word with the
value of each array member separated by the first character of the IFS
special variable, and ${name[@]} expands each element of name to a sep‐
arate word. When there are no array members, ${name[@]} expands to
So you can:
$ IFS=,; echo "${ids[*]}"
1,10
$
Also you can use sed to insert a whole line, like:
$ echo masi > foo
$ IFS=, sed -i "1i${ids[*]}" foo
$ cat foo
1,10
masi
$
IFS=, echo "${ids[*]}" would pass IFS=, to the environment of echo (which wouldn't do anything with it) and would not affect the expansion of "${ids[*]}". You'd need IFS=,; echo "${ids[*]}" or even better use zsh and do echo ${(j:,:)ids} that is use an explicit operator and avoid clobbering a default setting like $IFS.