I have to put in a bash variable the first line of a file. I guess it is with the grep command, but it is any way to restrict the number of lines?
Thanks in advance
+3
A:
head takes the first lines from a file, and the -n parameter can be used to specify how many lines should be extracted:
line=$(head -n 1 filename)
sth
2010-03-13 18:58:06
A:
line=$(head -1 file)
Will work fine. (As previous answer). But
line=$(read -r FIRSTLINE < filename)
will be marginally faster as read is a built-in bash command.
jackbot
2010-03-13 19:00:06
Please fix back-tick formatting
Tadeusz A. Kadłubowski
2010-03-13 19:01:40
Second method doesn't work as written, because `read` doesn't print anything (so `line` winds up blank), and also executes in a subshell (so `FIRSTLINE` gets set to the first line, but only in the subshell, so it's not available afterward). Solution: just use `read -r line <filename`
Gordon Davisson
2010-03-13 19:31:03
A:
to read first line using bash, use read statement. eg
read -r firstline<file
firstline will be your variable (No need to assign to another)
ghostdog74
2010-03-14 00:24:49