SHELL

linux use lines from file in command

# Basic syntax:
xargs -a file_to_read -I {} command {}
# Where:
#	- -a tells xargs to reads items from file_to_read instead of stdin.
#	- -I specifies a string that will be replaced by the stdin when found.
#		This is useful for controlling where the read content appears in the
#		xargs command
# Note, it's often useful to use this in conjunction with -n 1 and -P # which
#	causes xargs to run the commands in parallel using # processes

bash for each line of file

while read p; do
  echo "$p"
done <peptides.txt

read lines bash script

# Let's use a text file called file.txt
# the file contains 5 lines of some programming languages in use today:

$ cat file.txt
#Output:
#	JavaScript
#	Java
#	C
#	Python
#	C#


# Method 1 'wc'
# 'wc' command can be used to find the number of lines, characters,
# words, and bytes of a file.

$ wc -l file.txt

# Or

$ wc -l < file.txt

# Or

$ wc -l file.txt

# Output:
#	10 file.txt

# OR

# Method 2 - 'sed'
# 'sed' is a stream editor that can be used to perform basic text transformation 
# of an input file.
# This command is mostly used for find-and-replace functionality and 
# can also be used to find the number of lines of a specified file.

$ sed -n '=' file.txt
# Output:
#	1
#	2
#	3
#	4
#	5

# Or 

# sed -n '$='  which gives the overall number of lines
$ sed -n '$=' file.txt
# Output:
#	5

bash get line from file

sed 'NUMq;d' file

use lines from file for bash command

xargs -I{} curl "xyz.com/v1/"{} <file