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Using sed to remove text from a file

post #1 of 8

11/11/12 at 1:45pm

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Rubers
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I was to search a file for a particular string and delete it from the file.

Is sed the best way of doing this?

I've tried this:

Code:

#!/sbin/sh
busybox sed 's/String_1/ /' /system/file.txt
busybox sed 's/String_2/ /' /system/file.txt
busybox sed 's/String_3/ /' /system/file.txt

But it doesn't actually delete anything.

This:

Code:

#!/sbin/sh
busybox sed 's/String_1/ /' /system/file.txt > /system/file.txt
busybox sed 's/String_2/ /' /system/file.txt > /system/file.txt
busybox sed 's/String_3/ /' /system/file.txt > /system/file.txt

...deletes the whole file

I need to use busybox for this as it has be run on a Android device...

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CPU	Motherboard	Graphics	RAM
Intel Core i5 2500k 4.5GHz @ 1.31v	P8P67 PRO	MSI GTX670 Twin Frozr Power Edition OC 2GB	12GB (2x4GB 2x8GB) Mushkin Enhanced 1600MHz DDR3
Hard Drive	Hard Drive	Hard Drive	Hard Drive
OCZ Vertex 4 128GB SSD	1x320GB Western Digital Caviar Black	2x500GB Seagate Barracuda 7200RPM	Samsung Spinpoint F1 1TB
Hard Drive	Optical Drive	Cooling	OS
Seagate Barracuda 3TB 7200	Pioneer DVD-RW Drive	Coolermaster Hyper 212+	Windows 7 Professional 64bit
OS	Monitor	Keyboard	Power
Xubuntu 12.04 x86_64	Hanspree HG1115 1080p HDTV	Microsoft Curve	Coolermaster GX 550W
Case	Mouse	Mouse Pad	Audio
Coolermaster Storm Sniper	Coolermaster Storm Sentinel	Razer Goliathus	Creative XtremeGamer 7.1
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CPU	Graphics	RAM	Hard Drive
Exynos 4412 Quad Core ARMv7 Cortex-A9 @1.4GHz	ARM Mali-400 MP4	1 GB LP DDR2 Green Memory	Samsung KMVTU000LM eMMC(16GB)+MDDR(64MB) NAND F...
OS	Monitor
UltimaROM XXDLJ5 Jelly Bean 4.1.1	4.8" 720x1280 HD Super AMOLED
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post #2 of 8

11/11/12 at 2:38pm

Metmop
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Try this...

Code:

#!/sbin/sh
sed -e 's/String_1//' input_file > output_file
mv output_file input_file
sed -e 's/String_2//' input_file > output_file
mv output_file input_file
sed -e 's/String_3//' input_file > output_file
mv output_file input_file

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Samsung Spinpoint F3 1TB	Asus Cheapo	Corsair H70	Arch Linux
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LG 26LH20 HDTV	Das Model S Ultimate Silent	Corsair HX850	Lian Li(Lancool) PC-K62
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post #3 of 8

11/11/12 at 2:46pm

Thread Starter

Rubers
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Thanks, that's exactly what I needed

CPU	Motherboard	Graphics	RAM
Intel Core i5 2500k 4.5GHz @ 1.31v	P8P67 PRO	MSI GTX670 Twin Frozr Power Edition OC 2GB	12GB (2x4GB 2x8GB) Mushkin Enhanced 1600MHz DDR3
Hard Drive	Hard Drive	Hard Drive	Hard Drive
OCZ Vertex 4 128GB SSD	1x320GB Western Digital Caviar Black	2x500GB Seagate Barracuda 7200RPM	Samsung Spinpoint F1 1TB
Hard Drive	Optical Drive	Cooling	OS
Seagate Barracuda 3TB 7200	Pioneer DVD-RW Drive	Coolermaster Hyper 212+	Windows 7 Professional 64bit
OS	Monitor	Keyboard	Power
Xubuntu 12.04 x86_64	Hanspree HG1115 1080p HDTV	Microsoft Curve	Coolermaster GX 550W
Case	Mouse	Mouse Pad	Audio
Coolermaster Storm Sniper	Coolermaster Storm Sentinel	Razer Goliathus	Creative XtremeGamer 7.1
View all

CPU	Graphics	RAM	Hard Drive
Exynos 4412 Quad Core ARMv7 Cortex-A9 @1.4GHz	ARM Mali-400 MP4	1 GB LP DDR2 Green Memory	Samsung KMVTU000LM eMMC(16GB)+MDDR(64MB) NAND F...
OS	Monitor
UltimaROM XXDLJ5 Jelly Bean 4.1.1	4.8" 720x1280 HD Super AMOLED
View all

hide details

CPU	Motherboard	Graphics	RAM
Intel Core i5 2500k 4.5GHz @ 1.31v	P8P67 PRO	MSI GTX670 Twin Frozr Power Edition OC 2GB	12GB (2x4GB 2x8GB) Mushkin Enhanced 1600MHz DDR3
Hard Drive	Hard Drive	Hard Drive	Hard Drive
OCZ Vertex 4 128GB SSD	1x320GB Western Digital Caviar Black	2x500GB Seagate Barracuda 7200RPM	Samsung Spinpoint F1 1TB
Hard Drive	Optical Drive	Cooling	OS
Seagate Barracuda 3TB 7200	Pioneer DVD-RW Drive	Coolermaster Hyper 212+	Windows 7 Professional 64bit
OS	Monitor	Keyboard	Power
Xubuntu 12.04 x86_64	Hanspree HG1115 1080p HDTV	Microsoft Curve	Coolermaster GX 550W
Case	Mouse	Mouse Pad	Audio
Coolermaster Storm Sniper	Coolermaster Storm Sentinel	Razer Goliathus	Creative XtremeGamer 7.1
View all

CPU	Graphics	RAM	Hard Drive
Exynos 4412 Quad Core ARMv7 Cortex-A9 @1.4GHz	ARM Mali-400 MP4	1 GB LP DDR2 Green Memory	Samsung KMVTU000LM eMMC(16GB)+MDDR(64MB) NAND F...
OS	Monitor
UltimaROM XXDLJ5 Jelly Bean 4.1.1	4.8" 720x1280 HD Super AMOLED
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post #4 of 8

11/11/12 at 3:40pm

MJD
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An easier way is to use the -i flag. For instance:

Code:

busybox sed -i 's/String_1/ /' /system/file.txt
busybox sed -i 's/String_2/ /' /system/file.txt
busybox sed -i 's/String_3/ /' /system/file.txt

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post #5 of 8

11/11/12 at 5:11pm

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Rubers
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I went with:

Code:

#!/sbin/sh
sed -e '/BlahBlahBlah/d' /system/file.txt > /system/file.txt.bak

But it won't work via CWM for Android. Runs perfectly IN Android, but won't flash using Edify.

CPU	Motherboard	Graphics	RAM
Intel Core i5 2500k 4.5GHz @ 1.31v	P8P67 PRO	MSI GTX670 Twin Frozr Power Edition OC 2GB	12GB (2x4GB 2x8GB) Mushkin Enhanced 1600MHz DDR3
Hard Drive	Hard Drive	Hard Drive	Hard Drive
OCZ Vertex 4 128GB SSD	1x320GB Western Digital Caviar Black	2x500GB Seagate Barracuda 7200RPM	Samsung Spinpoint F1 1TB
Hard Drive	Optical Drive	Cooling	OS
Seagate Barracuda 3TB 7200	Pioneer DVD-RW Drive	Coolermaster Hyper 212+	Windows 7 Professional 64bit
OS	Monitor	Keyboard	Power
Xubuntu 12.04 x86_64	Hanspree HG1115 1080p HDTV	Microsoft Curve	Coolermaster GX 550W
Case	Mouse	Mouse Pad	Audio
Coolermaster Storm Sniper	Coolermaster Storm Sentinel	Razer Goliathus	Creative XtremeGamer 7.1
View all

CPU	Graphics	RAM	Hard Drive
Exynos 4412 Quad Core ARMv7 Cortex-A9 @1.4GHz	ARM Mali-400 MP4	1 GB LP DDR2 Green Memory	Samsung KMVTU000LM eMMC(16GB)+MDDR(64MB) NAND F...
OS	Monitor
UltimaROM XXDLJ5 Jelly Bean 4.1.1	4.8" 720x1280 HD Super AMOLED
View all

hide details

CPU	Motherboard	Graphics	RAM
Intel Core i5 2500k 4.5GHz @ 1.31v	P8P67 PRO	MSI GTX670 Twin Frozr Power Edition OC 2GB	12GB (2x4GB 2x8GB) Mushkin Enhanced 1600MHz DDR3
Hard Drive	Hard Drive	Hard Drive	Hard Drive
OCZ Vertex 4 128GB SSD	1x320GB Western Digital Caviar Black	2x500GB Seagate Barracuda 7200RPM	Samsung Spinpoint F1 1TB
Hard Drive	Optical Drive	Cooling	OS
Seagate Barracuda 3TB 7200	Pioneer DVD-RW Drive	Coolermaster Hyper 212+	Windows 7 Professional 64bit
OS	Monitor	Keyboard	Power
Xubuntu 12.04 x86_64	Hanspree HG1115 1080p HDTV	Microsoft Curve	Coolermaster GX 550W
Case	Mouse	Mouse Pad	Audio
Coolermaster Storm Sniper	Coolermaster Storm Sentinel	Razer Goliathus	Creative XtremeGamer 7.1
View all

CPU	Graphics	RAM	Hard Drive
Exynos 4412 Quad Core ARMv7 Cortex-A9 @1.4GHz	ARM Mali-400 MP4	1 GB LP DDR2 Green Memory	Samsung KMVTU000LM eMMC(16GB)+MDDR(64MB) NAND F...
OS	Monitor
UltimaROM XXDLJ5 Jelly Bean 4.1.1	4.8" 720x1280 HD Super AMOLED
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post #6 of 8

11/12/12 at 12:38am

Plan9
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if it's a whole line you're deleting, then you're probably better off using grep. sed comes into it's own when you're replacing text

post #7 of 8

11/12/12 at 3:11am

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Rubers
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Quote:

Originally Posted by Plan9

if it's a whole line you're deleting, then you're probably better off using grep. sed comes into it's own when you're replacing text

How would I do this?

CPU	Motherboard	Graphics	RAM
Intel Core i5 2500k 4.5GHz @ 1.31v	P8P67 PRO	MSI GTX670 Twin Frozr Power Edition OC 2GB	12GB (2x4GB 2x8GB) Mushkin Enhanced 1600MHz DDR3
Hard Drive	Hard Drive	Hard Drive	Hard Drive
OCZ Vertex 4 128GB SSD	1x320GB Western Digital Caviar Black	2x500GB Seagate Barracuda 7200RPM	Samsung Spinpoint F1 1TB
Hard Drive	Optical Drive	Cooling	OS
Seagate Barracuda 3TB 7200	Pioneer DVD-RW Drive	Coolermaster Hyper 212+	Windows 7 Professional 64bit
OS	Monitor	Keyboard	Power
Xubuntu 12.04 x86_64	Hanspree HG1115 1080p HDTV	Microsoft Curve	Coolermaster GX 550W
Case	Mouse	Mouse Pad	Audio
Coolermaster Storm Sniper	Coolermaster Storm Sentinel	Razer Goliathus	Creative XtremeGamer 7.1
View all

CPU	Graphics	RAM	Hard Drive
Exynos 4412 Quad Core ARMv7 Cortex-A9 @1.4GHz	ARM Mali-400 MP4	1 GB LP DDR2 Green Memory	Samsung KMVTU000LM eMMC(16GB)+MDDR(64MB) NAND F...
OS	Monitor
UltimaROM XXDLJ5 Jelly Bean 4.1.1	4.8" 720x1280 HD Super AMOLED
View all

hide details

CPU	Motherboard	Graphics	RAM
Intel Core i5 2500k 4.5GHz @ 1.31v	P8P67 PRO	MSI GTX670 Twin Frozr Power Edition OC 2GB	12GB (2x4GB 2x8GB) Mushkin Enhanced 1600MHz DDR3
Hard Drive	Hard Drive	Hard Drive	Hard Drive
OCZ Vertex 4 128GB SSD	1x320GB Western Digital Caviar Black	2x500GB Seagate Barracuda 7200RPM	Samsung Spinpoint F1 1TB
Hard Drive	Optical Drive	Cooling	OS
Seagate Barracuda 3TB 7200	Pioneer DVD-RW Drive	Coolermaster Hyper 212+	Windows 7 Professional 64bit
OS	Monitor	Keyboard	Power
Xubuntu 12.04 x86_64	Hanspree HG1115 1080p HDTV	Microsoft Curve	Coolermaster GX 550W
Case	Mouse	Mouse Pad	Audio
Coolermaster Storm Sniper	Coolermaster Storm Sentinel	Razer Goliathus	Creative XtremeGamer 7.1
View all

CPU	Graphics	RAM	Hard Drive
Exynos 4412 Quad Core ARMv7 Cortex-A9 @1.4GHz	ARM Mali-400 MP4	1 GB LP DDR2 Green Memory	Samsung KMVTU000LM eMMC(16GB)+MDDR(64MB) NAND F...
OS	Monitor
UltimaROM XXDLJ5 Jelly Bean 4.1.1	4.8" 720x1280 HD Super AMOLED
View all

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post #8 of 8

11/12/12 at 3:37am

Plan9
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Quote:

Originally Posted by Rubers

How would I do this?

Code:

grep -v "search string" input.txt

You may need to redirect to another file. eg

Code:

grep -v "search string" input.txt > output.txt

as grep might go a little odd if you're trying to modify a file while it's being read in.

[edit]

grep also supports regex.
Edited by Plan9 - 11/12/12 at 3:39am

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