Adding leading zeroes to text in a file

[ecbakken]

Hello all,

I'm creating a tag file and need to fill in a 4 digit field with a number and leading zeros. For example, I would need to turn this:

74 

5

143

into this:

0074

0005

0143

Is this possible? Thanks,

-Eric

[Steven Schweda · Accepted solution]

> I'm creating a tag file [...]

   Tells me approximately nothing.  I'll assume a shell script to
process an existing file.

   Not very efficient, but...

$ cat nlz.txt
74
5
143

$ (  while read line ; do echo "0000$line" | sed -e 's/.*\(....\)/\1/' ; done ) < nlz.txt
0074
0005
0143

[ecbakken]

I'm sorry for the lack of information and I commend your assumption skills. This is exactly what I needed. Thank you.

[James R. Ferguson]

Hi:

Another way:

# while read line;do printf "%04d\n" $line;done < file

Regards!

...JRF...

[Dennis Handly]

If you want leading zeros in your shell variables, you can use:

typeset -Z4 variable=0

echo $variable

0000

In your case you can read your file and assign to "variable" and then print it out.

for variable in $(< file); do

   echo $variable

done